| Value | Category | Cases | |
|---|---|---|---|
| -99 | DK | 1 |
0.1%
|
| -88 | Missing | 1 |
0.1%
|
| -77 | NA | 5 |
0.3%
|
| 1964 | 1 |
0.1%
|
|
| 1969 | 1 |
0.1%
|
|
| 1970 | 1 |
0.1%
|
|
| 1975 | 1 |
0.1%
|
|
| 1977 | 1 |
0.1%
|
|
| 1978 | 1 |
0.1%
|
|
| 1980 | 2 |
0.1%
|
|
| 1982 | 4 |
0.3%
|
|
| 1983 | 3 |
0.2%
|
|
| 1984 | 4 |
0.3%
|
|
| 1985 | 2 |
0.1%
|
|
| 1986 | 5 |
0.3%
|
|
| 1988 | 2 |
0.1%
|
|
| 1989 | 5 |
0.3%
|
|
| 1990 | 6 |
0.4%
|
|
| 1991 | 3 |
0.2%
|
|
| 1992 | 9 |
0.6%
|
|
| 1993 | 6 |
0.4%
|
|
| 1994 | 12 |
0.8%
|
|
| 1995 | 20 |
1.3%
|
|
| 1996 | 54 |
3.4%
|
|
| 1997 | 138 |
8.8%
|
|
| 1998 | 423 |
26.9%
|
|
| 1999 | 458 |
29.1%
|
|
| 2000 | 402 |
25.6%
|
|
| 2001 | 1 |
0.1%
|
|
| Sysmiss | 3 |