| Value |
Category |
| 1 |
2003 or earlier |
| 2 |
2004 |
| 3 |
2005 |
| 4 |
2006 |
| 5 |
2007 |
| 6 |
2008 |
| 7 |
2009 |
| 8 |
2010 (this year) |
| 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.