| Value | Category | Cases | |
|---|---|---|---|
| 1977 | 3 |
10%
|
|
| 1981 | 1 |
3.3%
|
|
| 1986 | 1 |
3.3%
|
|
| 1987 | 1 |
3.3%
|
|
| 1988 | 1 |
3.3%
|
|
| 1989 | 2 |
6.7%
|
|
| 1991 | 4 |
13.3%
|
|
| 1992 | 1 |
3.3%
|
|
| 1993 | 3 |
10%
|
|
| 1994 | 1 |
3.3%
|
|
| 1995 | 4 |
13.3%
|
|
| 1996 | 2 |
6.7%
|
|
| 1998 | 1 |
3.3%
|
|
| 2004 | 1 |
3.3%
|
|
| 2005 | 1 |
3.3%
|
|
| 2008 | 2 |
6.7%
|
|
| 2012 | 1 |
3.3%
|
|
| 9998 | don't know | 0 |
0%
|
| Sysmiss | 16400 |