| value | category | cases | |
|---|---|---|---|
| 1973 | 2 |
1.4%
|
|
| 1975 | 2 |
1.4%
|
|
| 1978 | 1 |
0.7%
|
|
| 1979 | 1 |
0.7%
|
|
| 1980 | 2 |
1.4%
|
|
| 1982 | 1 |
0.7%
|
|
| 1983 | 4 |
2.8%
|
|
| 1984 | 4 |
2.8%
|
|
| 1985 | 6 |
4.3%
|
|
| 1986 | 4 |
2.8%
|
|
| 1987 | 4 |
2.8%
|
|
| 1988 | 6 |
4.3%
|
|
| 1989 | 3 |
2.1%
|
|
| 1990 | 15 |
10.6%
|
|
| 1991 | 5 |
3.5%
|
|
| 1992 | 6 |
4.3%
|
|
| 1993 | 20 |
14.2%
|
|
| 1994 | 12 |
8.5%
|
|
| 1995 | 11 |
7.8%
|
|
| 1996 | 16 |
11.3%
|
|
| 1997 | 16 |
11.3%
|
|
| 9997 | Inconsistent | 0 |
0%
|
| 9998 | Don't know | 0 |
0%
|
| Sysmiss | 2199 |