| Value | Category | Cases | |
|---|---|---|---|
| 1971 | 1 | 
                                                                 
                                    
                                    0.2%
                                 
                                                             | 
                                                        
                    |
| 1974 | 2 | 
                                                                 
                                    
                                    0.3%
                                 
                                                             | 
                                                        
                    |
| 1975 | 1 | 
                                                                 
                                    
                                    0.2%
                                 
                                                             | 
                                                        
                    |
| 1976 | 1 | 
                                                                 
                                    
                                    0.2%
                                 
                                                             | 
                                                        
                    |
| 1977 | 2 | 
                                                                 
                                    
                                    0.3%
                                 
                                                             | 
                                                        
                    |
| 1978 | 3 | 
                                                                 
                                    
                                    0.5%
                                 
                                                             | 
                                                        
                    |
| 1979 | 3 | 
                                                                 
                                    
                                    0.5%
                                 
                                                             | 
                                                        
                    |
| 1980 | 7 | 
                                                                 
                                    
                                    1.2%
                                 
                                                             | 
                                                        
                    |
| 1981 | 6 | 
                                                                 
                                    
                                    1%
                                 
                                                             | 
                                                        
                    |
| 1982 | 9 | 
                                                                 
                                    
                                    1.5%
                                 
                                                             | 
                                                        
                    |
| 1983 | 5 | 
                                                                 
                                    
                                    0.8%
                                 
                                                             | 
                                                        
                    |
| 1984 | 11 | 
                                                                 
                                    
                                    1.8%
                                 
                                                             | 
                                                        
                    |
| 1985 | 3 | 
                                                                 
                                    
                                    0.5%
                                 
                                                             | 
                                                        
                    |
| 1986 | 10 | 
                                                                 
                                    
                                    1.7%
                                 
                                                             | 
                                                        
                    |
| 1987 | 7 | 
                                                                 
                                    
                                    1.2%
                                 
                                                             | 
                                                        
                    |
| 1988 | 7 | 
                                                                 
                                    
                                    1.2%
                                 
                                                             | 
                                                        
                    |
| 1989 | 10 | 
                                                                 
                                    
                                    1.7%
                                 
                                                             | 
                                                        
                    |
| 1990 | 14 | 
                                                                 
                                    
                                    2.3%
                                 
                                                             | 
                                                        
                    |
| 1991 | 15 | 
                                                                 
                                    
                                    2.5%
                                 
                                                             | 
                                                        
                    |
| 1992 | 14 | 
                                                                 
                                    
                                    2.3%
                                 
                                                             | 
                                                        
                    |
| 1993 | 10 | 
                                                                 
                                    
                                    1.7%
                                 
                                                             | 
                                                        
                    |
| 1994 | 12 | 
                                                                 
                                    
                                    2%
                                 
                                                             | 
                                                        
                    |
| 1995 | 17 | 
                                                                 
                                    
                                    2.8%
                                 
                                                             | 
                                                        
                    |
| 1996 | 17 | 
                                                                 
                                    
                                    2.8%
                                 
                                                             | 
                                                        
                    |
| 1997 | 10 | 
                                                                 
                                    
                                    1.7%
                                 
                                                             | 
                                                        
                    |
| 1998 | 16 | 
                                                                 
                                    
                                    2.7%
                                 
                                                             | 
                                                        
                    |
| 1999 | 15 | 
                                                                 
                                    
                                    2.5%
                                 
                                                             | 
                                                        
                    |
| 2000 | 25 | 
                                                                 
                                    
                                    4.2%
                                 
                                                             | 
                                                        
                    |
| 2001 | 18 | 
                                                                 
                                    
                                    3%
                                 
                                                             | 
                                                        
                    |
| 2002 | 20 | 
                                                                 
                                    
                                    3.4%
                                 
                                                             | 
                                                        
                    |
| 2003 | 10 | 
                                                                 
                                    
                                    1.7%
                                 
                                                             | 
                                                        
                    |
| 2004 | 23 | 
                                                                 
                                    
                                    3.9%
                                 
                                                             | 
                                                        
                    |
| 2005 | 21 | 
                                                                 
                                    
                                    3.5%
                                 
                                                             | 
                                                        
                    |
| 2006 | 22 | 
                                                                 
                                    
                                    3.7%
                                 
                                                             | 
                                                        
                    |
| 2007 | 24 | 
                                                                 
                                    
                                    4%
                                 
                                                             | 
                                                        
                    |
| 2008 | 17 | 
                                                                 
                                    
                                    2.8%
                                 
                                                             | 
                                                        
                    |
| 2009 | 19 | 
                                                                 
                                    
                                    3.2%
                                 
                                                             | 
                                                        
                    |
| 2010 | 31 | 
                                                                 
                                    
                                    5.2%
                                 
                                                             | 
                                                        
                    |
| 2011 | 31 | 
                                                                 
                                    
                                    5.2%
                                 
                                                             | 
                                                        
                    |
| 2012 | 37 | 
                                                                 
                                    
                                    6.2%
                                 
                                                             | 
                                                        
                    |
| 2013 | 31 | 
                                                                 
                                    
                                    5.2%
                                 
                                                             | 
                                                        
                    |
| 2014 | 18 | 
                                                                 
                                    
                                    3%
                                 
                                                             | 
                                                        
                    |
| 9997 | Inconsistent | 0 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| 9998 | DK | 21 | 
                                                                 
                                    
                                    3.5%
                                 
                                                             | 
                                                        
                    
| 9999 | Missing | 1 | 
                                                                 
                                    
                                    0.2%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 1032 |