| Value | Category | Cases | |
|---|---|---|---|
| 0 | none | 0 |
0%
|
| 777 | n\a | 0 |
0%
|
| 999 | missing | 0 |
0%
|
| 1971 | 2 |
2.9%
|
|
| 1978 | 2 |
2.9%
|
|
| 1986 | 1 |
1.5%
|
|
| 1988 | 1 |
1.5%
|
|
| 1990 | 1 |
1.5%
|
|
| 1992 | 1 |
1.5%
|
|
| 1994 | 1 |
1.5%
|
|
| 1995 | 2 |
2.9%
|
|
| 1996 | 1 |
1.5%
|
|
| 1998 | 1 |
1.5%
|
|
| 1999 | 4 |
5.9%
|
|
| 2000 | 4 |
5.9%
|
|
| 2001 | 4 |
5.9%
|
|
| 2002 | 2 |
2.9%
|
|
| 2003 | 4 |
5.9%
|
|
| 2004 | 6 |
8.8%
|
|
| 2005 | 6 |
8.8%
|
|
| 2006 | 7 |
10.3%
|
|
| 2007 | 4 |
5.9%
|
|
| 2008 | 12 |
17.6%
|
|
| 2009 | 1 |
1.5%
|
|
| 200711 | 1 |
1.5%
|
|
| Sysmiss | 2 |