| value | category | cases | |
|---|---|---|---|
| 1968 | 1 |
0.6%
|
|
| 1969 | 2 |
1.3%
|
|
| 1970 | 1 |
0.6%
|
|
| 1971 | 5 |
3.1%
|
|
| 1972 | 5 |
3.1%
|
|
| 1973 | 10 |
6.3%
|
|
| 1974 | 12 |
7.5%
|
|
| 1975 | 16 |
10%
|
|
| 1976 | 19 |
11.9%
|
|
| 1977 | 20 |
12.5%
|
|
| 1978 | 18 |
11.3%
|
|
| 1979 | 14 |
8.8%
|
|
| 1980 | 12 |
7.5%
|
|
| 1981 | 9 |
5.6%
|
|
| 1982 | 7 |
4.4%
|
|
| 1983 | 4 |
2.5%
|
|
| 1985 | 3 |
1.9%
|
|
| 1986 | 2 |
1.3%
|
|
| Sysmiss | 12317 |