| Value | Category | Cases | |
|---|---|---|---|
| 1 | NEVER | 8591 |
14.3%
|
| 2 | BEFORE 2003 | 9442 |
15.8%
|
| 3 | 2003 | 3595 |
6%
|
| 4 | 2004 | 3898 |
6.5%
|
| 5 | 2005 | 7388 |
12.3%
|
| 6 | 2006 | 13441 |
22.5%
|
| 7 | 2007 | 13513 |
22.6%
|
| 9 | OMITTED | 0 |
0%
|
| Sysmiss | 1528 |