Value |
Category |
-9 |
don't know |
1981 |
|
1987 |
|
1989 |
|
1991 |
|
1994 |
|
1995 |
|
1997 |
|
2001 |
|
2002 |
|
2003 |
|
2004 |
|
2006 |
|
2007 |
|
2008 |
|
Sysmiss |
|
Warning: these figures indicate the number of cases found in the data file. They cannot be interpreted as summary statistics of the population of interest.