| Value | Category | Cases | |
|---|---|---|---|
| 1959 | 1 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    |
| 1970 | 1 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    |
| 1978 | 1 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    |
| 1979 | 370 | 
                                                                 
                                    
                                    9.8%
                                 
                                                             | 
                                                        
                    |
| 1980 | 223 | 
                                                                 
                                    
                                    5.9%
                                 
                                                             | 
                                                        
                    |
| 1981 | 110 | 
                                                                 
                                    
                                    2.9%
                                 
                                                             | 
                                                        
                    |
| 1982 | 195 | 
                                                                 
                                    
                                    5.2%
                                 
                                                             | 
                                                        
                    |
| 1983 | 210 | 
                                                                 
                                    
                                    5.6%
                                 
                                                             | 
                                                        
                    |
| 1984 | 152 | 
                                                                 
                                    
                                    4%
                                 
                                                             | 
                                                        
                    |
| 1985 | 100 | 
                                                                 
                                    
                                    2.6%
                                 
                                                             | 
                                                        
                    |
| 1986 | 81 | 
                                                                 
                                    
                                    2.1%
                                 
                                                             | 
                                                        
                    |
| 1987 | 70 | 
                                                                 
                                    
                                    1.9%
                                 
                                                             | 
                                                        
                    |
| 1988 | 40 | 
                                                                 
                                    
                                    1.1%
                                 
                                                             | 
                                                        
                    |
| 1989 | 32 | 
                                                                 
                                    
                                    0.8%
                                 
                                                             | 
                                                        
                    |
| 1990 | 119 | 
                                                                 
                                    
                                    3.1%
                                 
                                                             | 
                                                        
                    |
| 1991 | 42 | 
                                                                 
                                    
                                    1.1%
                                 
                                                             | 
                                                        
                    |
| 1992 | 96 | 
                                                                 
                                    
                                    2.5%
                                 
                                                             | 
                                                        
                    |
| 1993 | 124 | 
                                                                 
                                    
                                    3.3%
                                 
                                                             | 
                                                        
                    |
| 1994 | 75 | 
                                                                 
                                    
                                    2%
                                 
                                                             | 
                                                        
                    |
| 1995 | 77 | 
                                                                 
                                    
                                    2%
                                 
                                                             | 
                                                        
                    |
| 1996 | 53 | 
                                                                 
                                    
                                    1.4%
                                 
                                                             | 
                                                        
                    |
| 1997 | 74 | 
                                                                 
                                    
                                    2%
                                 
                                                             | 
                                                        
                    |
| 1998 | 101 | 
                                                                 
                                    
                                    2.7%
                                 
                                                             | 
                                                        
                    |
| 1999 | 101 | 
                                                                 
                                    
                                    2.7%
                                 
                                                             | 
                                                        
                    |
| 2000 | 174 | 
                                                                 
                                    
                                    4.6%
                                 
                                                             | 
                                                        
                    |
| 2001 | 70 | 
                                                                 
                                    
                                    1.9%
                                 
                                                             | 
                                                        
                    |
| 2002 | 122 | 
                                                                 
                                    
                                    3.2%
                                 
                                                             | 
                                                        
                    |
| 2003 | 69 | 
                                                                 
                                    
                                    1.8%
                                 
                                                             | 
                                                        
                    |
| 2004 | 64 | 
                                                                 
                                    
                                    1.7%
                                 
                                                             | 
                                                        
                    |
| 2005 | 107 | 
                                                                 
                                    
                                    2.8%
                                 
                                                             | 
                                                        
                    |
| 2006 | 98 | 
                                                                 
                                    
                                    2.6%
                                 
                                                             | 
                                                        
                    |
| 2007 | 128 | 
                                                                 
                                    
                                    3.4%
                                 
                                                             | 
                                                        
                    |
| 2008 | 130 | 
                                                                 
                                    
                                    3.4%
                                 
                                                             | 
                                                        
                    |
| 2009 | 138 | 
                                                                 
                                    
                                    3.6%
                                 
                                                             | 
                                                        
                    |
| 2010 | 120 | 
                                                                 
                                    
                                    3.2%
                                 
                                                             | 
                                                        
                    |
| 2011 | 86 | 
                                                                 
                                    
                                    2.3%
                                 
                                                             | 
                                                        
                    |
| 2012 | 27 | 
                                                                 
                                    
                                    0.7%
                                 
                                                             |