Value | Category |
---|---|
5 | None |
7 | Can't remember |
9 | Don't know/Didn't say |
1960 | |
1965 | |
1966 | |
1970 | |
1973 | |
1975 | |
1977 | |
1980 | |
1981 | |
1982 | |
1983 | |
1984 | |
1985 | |
1986 | |
1987 | |
1989 | |
1990 | |
1992 | |
1993 | |
1994 | |
1995 | |
1996 | |
1997 | |
1998 | |
1999 | |
2000 | |
2001 | |
2002 | |
2003 | |
2004 | |
2005 | |
9997 | |
Sysmiss |