| Value | Category | Cases | |
|---|---|---|---|
| -2 | Refusal to answer | 0 |
0%
|
| -1 | Don't know | 1 |
0.1%
|
| 1953 | 1 |
0.1%
|
|
| 1957 | 2 |
0.1%
|
|
| 1960 | 3 |
0.2%
|
|
| 1963 | 1 |
0.1%
|
|
| 1964 | 5 |
0.3%
|
|
| 1965 | 3 |
0.2%
|
|
| 1966 | 3 |
0.2%
|
|
| 1967 | 3 |
0.2%
|
|
| 1968 | 4 |
0.2%
|
|
| 1969 | 10 |
0.5%
|
|
| 1970 | 20 |
1%
|
|
| 1971 | 14 |
0.7%
|
|
| 1972 | 15 |
0.8%
|
|
| 1973 | 19 |
1%
|
|
| 1974 | 25 |
1.3%
|
|
| 1975 | 38 |
1.9%
|
|
| 1976 | 32 |
1.6%
|
|
| 1977 | 33 |
1.7%
|
|
| 1978 | 31 |
1.6%
|
|
| 1979 | 42 |
2.1%
|
|
| 1980 | 62 |
3.2%
|
|
| 1981 | 55 |
2.8%
|
|
| 1982 | 69 |
3.5%
|
|
| 1983 | 66 |
3.4%
|
|
| 1984 | 59 |
3%
|
|
| 1985 | 85 |
4.3%
|
|
| 1986 | 70 |
3.6%
|
|
| 1987 | 62 |
3.2%
|
|
| 1988 | 78 |
4%
|
|
| 1989 | 95 |
4.8%
|
|
| 1990 | 134 |
6.8%
|
|
| 1991 | 95 |
4.8%
|
|
| 1992 | 92 |
4.7%
|
|
| 1993 | 65 |
3.3%
|
|
| 1994 | 56 |
2.9%
|
|
| 1995 | 86 |
4.4%
|
|
| 1996 | 69 |
3.5%
|
|
| 1997 | 100 |
5.1%
|
|
| 1998 | 84 |
4.3%
|
|
| 1999 | 91 |
4.6%
|
|
| 2000 | 70 |
3.6%
|
|
| 2001 | 16 |
0.8%
|
|
| Sysmiss | 12 |