| value | category | cases | |
|---|---|---|---|
| 1968 | 1 |
0.3%
|
|
| 1972 | 1 |
0.3%
|
|
| 1973 | 2 |
0.5%
|
|
| 1975 | 2 |
0.5%
|
|
| 1978 | 2 |
0.5%
|
|
| 1979 | 3 |
0.8%
|
|
| 1980 | 6 |
1.6%
|
|
| 1981 | 1 |
0.3%
|
|
| 1982 | 4 |
1.1%
|
|
| 1983 | 8 |
2.1%
|
|
| 1984 | 4 |
1.1%
|
|
| 1985 | 6 |
1.6%
|
|
| 1986 | 7 |
1.9%
|
|
| 1987 | 7 |
1.9%
|
|
| 1988 | 6 |
1.6%
|
|
| 1989 | 5 |
1.3%
|
|
| 1990 | 16 |
4.2%
|
|
| 1991 | 10 |
2.6%
|
|
| 1992 | 8 |
2.1%
|
|
| 1993 | 22 |
5.8%
|
|
| 1994 | 14 |
3.7%
|
|
| 1995 | 19 |
5%
|
|
| 1996 | 20 |
5.3%
|
|
| 1997 | 18 |
4.8%
|
|
| 1998 | 37 |
9.8%
|
|
| 1999 | 32 |
8.5%
|
|
| 2000 | 32 |
8.5%
|
|
| 2001 | 23 |
6.1%
|
|
| 2002 | 33 |
8.7%
|
|
| 2003 | 29 |
7.7%
|
|
| 9997 | Inconsistent | 0 |
0%
|
| 9998 | DK | 0 |
0%
|
| Sysmiss | 1962 |