Value |
Category |
1 |
2010-2012 |
2 |
2007-2009 |
3 |
2004-2006 |
4 |
2001-2003 |
5 |
1998-2000 |
6 |
Below 1997 |
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.