| Value | Category | Cases | |
|---|---|---|---|
| 1960 | 1 | 
                                    
                                    0.2%
                                 | |
| 1964 | 1 | 
                                    
                                    0.2%
                                 | |
| 1965 | 1 | 
                                    
                                    0.2%
                                 | |
| 1966 | 1 | 
                                    
                                    0.2%
                                 | |
| 1967 | 1 | 
                                    
                                    0.2%
                                 | |
| 1968 | 2 | 
                                    
                                    0.4%
                                 | |
| 1969 | 2 | 
                                    
                                    0.4%
                                 | |
| 1970 | 2 | 
                                    
                                    0.4%
                                 | |
| 1973 | 1 | 
                                    
                                    0.2%
                                 | |
| 1974 | 1 | 
                                    
                                    0.2%
                                 | |
| 1975 | 3 | 
                                    
                                    0.6%
                                 | |
| 1976 | 1 | 
                                    
                                    0.2%
                                 | |
| 1977 | 2 | 
                                    
                                    0.4%
                                 | |
| 1980 | 2 | 
                                    
                                    0.4%
                                 | |
| 1982 | 1 | 
                                    
                                    0.2%
                                 | |
| 1983 | 3 | 
                                    
                                    0.6%
                                 | |
| 1984 | 6 | 
                                    
                                    1.2%
                                 | |
| 1985 | 4 | 
                                    
                                    0.8%
                                 | |
| 1986 | 6 | 
                                    
                                    1.2%
                                 | |
| 1988 | 9 | 
                                    
                                    1.8%
                                 | |
| 1989 | 5 | 
                                    
                                    1%
                                 | |
| 1990 | 2 | 
                                    
                                    0.4%
                                 | |
| 1991 | 6 | 
                                    
                                    1.2%
                                 | |
| 1992 | 7 | 
                                    
                                    1.4%
                                 | |
| 1993 | 3 | 
                                    
                                    0.6%
                                 | |
| 1994 | 2 | 
                                    
                                    0.4%
                                 | |
| 1995 | 6 | 
                                    
                                    1.2%
                                 | |
| 1996 | 6 | 
                                    
                                    1.2%
                                 | |
| 1997 | 7 | 
                                    
                                    1.4%
                                 | |
| 1998 | 5 | 
                                    
                                    1%
                                 | |
| 1999 | 2 | 
                                    
                                    0.4%
                                 | |
| 2000 | 12 | 
                                    
                                    2.4%
                                 | |
| 2001 | 5 | 
                                    
                                    1%
                                 | |
| 2002 | 5 | 
                                    
                                    1%
                                 | |
| 2003 | 1 | 
                                    
                                    0.2%
                                 | |
| 2004 | 9 | 
                                    
                                    1.8%
                                 | |
| 2005 | 10 | 
                                    
                                    2%
                                 | |
| 2006 | 20 | 
                                    
                                    4%
                                 | |
| 2007 | 19 | 
                                    
                                    3.8%
                                 | |
| 2008 | 22 | 
                                    
                                    4.4%
                                 | |
| 2009 | 37 | 
                                    
                                    7.4%
                                 | |
| 2010 | 50 | 
                                    
                                    10%
                                 | |
| 2011 | 51 | 
                                    
                                    10.2%
                                 | |
| 2012 | 55 | 
                                    
                                    11%
                                 | |
| 2013 | 53 | 
                                    
                                    10.6%
                                 | |
| 2014 | 30 | 
                                    
                                    6%
                                 | |
| 2015 | 2 | 
                                    
                                    0.4%
                                 | |
| 9999 | DON'T KNOW | 17 | 
                                    
                                    3.4%
                                 | 
| Sysmiss | 4243 |