| Value |
Category |
| 1 |
2008-2012 |
| 2 |
2003-2007 |
| 3 |
1998-2002 |
| 4 |
1993-1997 |
| 5 |
1988-1992 |
| 6 |
1983-1987 |
| 7 |
Below 1983 |
| 9 |
Not specified |
| 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.