| Value | Category | Cases | |
|---|---|---|---|
| 1968 | 28 | 
                                    
                                    0.1%
                                 | |
| 1969 | 196 | 
                                    
                                    1%
                                 | |
| 1970 | 263 | 
                                    
                                    1.4%
                                 | |
| 1971 | 200 | 
                                    
                                    1.1%
                                 | |
| 1972 | 305 | 
                                    
                                    1.6%
                                 | |
| 1973 | 309 | 
                                    
                                    1.6%
                                 | |
| 1974 | 268 | 
                                    
                                    1.4%
                                 | |
| 1975 | 327 | 
                                    
                                    1.7%
                                 | |
| 1976 | 329 | 
                                    
                                    1.7%
                                 | |
| 1977 | 312 | 
                                    
                                    1.7%
                                 | |
| 1978 | 500 | 
                                    
                                    2.7%
                                 | |
| 1979 | 349 | 
                                    
                                    1.9%
                                 | |
| 1980 | 465 | 
                                    
                                    2.5%
                                 | |
| 1981 | 321 | 
                                    
                                    1.7%
                                 | |
| 1982 | 371 | 
                                    
                                    2%
                                 | |
| 1983 | 474 | 
                                    
                                    2.5%
                                 | |
| 1984 | 359 | 
                                    
                                    1.9%
                                 | |
| 1985 | 382 | 
                                    
                                    2%
                                 | |
| 1986 | 452 | 
                                    
                                    2.4%
                                 | |
| 1987 | 379 | 
                                    
                                    2%
                                 | |
| 1988 | 565 | 
                                    
                                    3%
                                 | |
| 1989 | 400 | 
                                    
                                    2.1%
                                 | |
| 1990 | 642 | 
                                    
                                    3.4%
                                 | |
| 1991 | 458 | 
                                    
                                    2.4%
                                 | |
| 1992 | 574 | 
                                    
                                    3.1%
                                 | |
| 1993 | 647 | 
                                    
                                    3.4%
                                 | |
| 1994 | 544 | 
                                    
                                    2.9%
                                 | |
| 1995 | 580 | 
                                    
                                    3.1%
                                 | |
| 1996 | 580 | 
                                    
                                    3.1%
                                 | |
| 1997 | 584 | 
                                    
                                    3.1%
                                 | |
| 1998 | 897 | 
                                    
                                    4.8%
                                 | |
| 1999 | 768 | 
                                    
                                    4.1%
                                 | |
| 2000 | 1059 | 
                                    
                                    5.6%
                                 | |
| 2001 | 682 | 
                                    
                                    3.6%
                                 | |
| 2002 | 811 | 
                                    
                                    4.3%
                                 | |
| 2003 | 672 | 
                                    
                                    3.6%
                                 | |
| 9998 | NSP | 106 | 
                                    
                                    0.6%
                                 | 
| 9999 | NON REPONSE | 5 | 
                                    
                                    0%
                                 | 
| Sysmiss | 1649 | 
                                    
                                    8.8%
                                 |