| Value | Category | Cases | |
|---|---|---|---|
| 1968 | 264 | 
                                    
                                    0.9%
                                 | |
| 1969 | 482 | 
                                    
                                    1.6%
                                 | |
| 1970 | 559 | 
                                    
                                    1.8%
                                 | |
| 1971 | 563 | 
                                    
                                    1.8%
                                 | |
| 1972 | 692 | 
                                    
                                    2.3%
                                 | |
| 1973 | 633 | 
                                    
                                    2.1%
                                 | |
| 1974 | 672 | 
                                    
                                    2.2%
                                 | |
| 1975 | 645 | 
                                    
                                    2.1%
                                 | |
| 1976 | 637 | 
                                    
                                    2.1%
                                 | |
| 1977 | 669 | 
                                    
                                    2.2%
                                 | |
| 1978 | 696 | 
                                    
                                    2.3%
                                 | |
| 1979 | 731 | 
                                    
                                    2.4%
                                 | |
| 1980 | 809 | 
                                    
                                    2.6%
                                 | |
| 1981 | 737 | 
                                    
                                    2.4%
                                 | |
| 1982 | 775 | 
                                    
                                    2.5%
                                 | |
| 1983 | 809 | 
                                    
                                    2.6%
                                 | |
| 1984 | 824 | 
                                    
                                    2.7%
                                 | |
| 1985 | 900 | 
                                    
                                    2.9%
                                 | |
| 1986 | 788 | 
                                    
                                    2.6%
                                 | |
| 1987 | 810 | 
                                    
                                    2.6%
                                 | |
| 1988 | 823 | 
                                    
                                    2.7%
                                 | |
| 1989 | 915 | 
                                    
                                    3%
                                 | |
| 1990 | 1074 | 
                                    
                                    3.5%
                                 | |
| 1991 | 881 | 
                                    
                                    2.9%
                                 | |
| 1992 | 939 | 
                                    
                                    3.1%
                                 | |
| 1993 | 1037 | 
                                    
                                    3.4%
                                 | |
| 1994 | 1099 | 
                                    
                                    3.6%
                                 | |
| 1995 | 1048 | 
                                    
                                    3.4%
                                 | |
| 1996 | 1093 | 
                                    
                                    3.6%
                                 | |
| 1997 | 1200 | 
                                    
                                    3.9%
                                 | |
| 1998 | 1192 | 
                                    
                                    3.9%
                                 | |
| 1999 | 1255 | 
                                    
                                    4.1%
                                 | |
| 2000 | 1327 | 
                                    
                                    4.3%
                                 | |
| 2001 | 1312 | 
                                    
                                    4.3%
                                 | |
| 2002 | 1322 | 
                                    
                                    4.3%
                                 | |
| 2003 | 446 | 
                                    
                                    1.5%
                                 | |
| 9998 | DK | 1 | 
                                    
                                    0%
                                 | 
| 9999 | NO RESPONSE | 1 | 
                                    
                                    0%
                                 | 
| Sysmiss | 400 |