| Value | Category | Cases | |
|---|---|---|---|
| 1970 | 6 |
0%
|
|
| 1971 | 6 |
0%
|
|
| 1972 | 20 |
0.1%
|
|
| 1973 | 30 |
0.2%
|
|
| 1974 | 65 |
0.4%
|
|
| 1975 | 83 |
0.6%
|
|
| 1976 | 110 |
0.7%
|
|
| 1977 | 157 |
1.1%
|
|
| 1978 | 207 |
1.4%
|
|
| 1979 | 268 |
1.8%
|
|
| 1980 | 358 |
2.4%
|
|
| 1981 | 331 |
2.2%
|
|
| 1982 | 329 |
2.2%
|
|
| 1983 | 404 |
2.7%
|
|
| 1984 | 377 |
2.5%
|
|
| 1985 | 410 |
2.8%
|
|
| 1986 | 427 |
2.9%
|
|
| 1987 | 422 |
2.8%
|
|
| 1988 | 450 |
3%
|
|
| 1989 | 485 |
3.3%
|
|
| 1990 | 530 |
3.6%
|
|
| 1991 | 473 |
3.2%
|
|
| 1992 | 518 |
3.5%
|
|
| 1993 | 531 |
3.6%
|
|
| 1994 | 567 |
3.8%
|
|
| 1995 | 551 |
3.7%
|
|
| 1996 | 570 |
3.8%
|
|
| 1997 | 542 |
3.6%
|
|
| 1998 | 617 |
4.1%
|
|
| 1999 | 596 |
4%
|
|
| 2000 | 693 |
4.6%
|
|
| 2001 | 582 |
3.9%
|
|
| 2002 | 611 |
4.1%
|
|
| 2003 | 649 |
4.4%
|
|
| 2004 | 605 |
4.1%
|
|
| 2005 | 601 |
4%
|
|
| 2006 | 551 |
3.7%
|
|
| 2007 | 121 |
0.8%
|
|
| 9997 | Inconsistent | 5 |
0%
|
| 9998 | Don't know year | 47 |
0.3%
|
| 9999 | 4 |