| Value | Category | Cases | |
|---|---|---|---|
| 1983 | 1 |
0.2%
|
|
| 1984 | 5 |
1.2%
|
|
| 1985 | 3 |
0.7%
|
|
| 1986 | 10 |
2.4%
|
|
| 1987 | 14 |
3.4%
|
|
| 1988 | 17 |
4.1%
|
|
| 1989 | 26 |
6.3%
|
|
| 1990 | 27 |
6.5%
|
|
| 1991 | 45 |
10.9%
|
|
| 1992 | 42 |
10.1%
|
|
| 1993 | 49 |
11.8%
|
|
| 1994 | 60 |
14.5%
|
|
| 1995 | 45 |
10.9%
|
|
| 1996 | 29 |
7%
|
|
| 1997 | 41 |
9.9%
|
|
| 9995 | 9995. Topcode | 0 |
0%
|
| 9996 | 9996. N/A | 0 |
0%
|
| 9997 | 9997. Refuse | 0 |
0%
|
| 9998 | 9998. DK | 0 |
0%
|
| 9999 | 9999. Miss | 0 |
0%
|
| Sysmiss | 416 |