| Value | Category | Cases | |
|---|---|---|---|
| 0 | was here | 405 |
86.4%
|
| 1972 | 1 |
0.2%
|
|
| 1977 | 1 |
0.2%
|
|
| 1980 | 1 |
0.2%
|
|
| 1981 | 3 |
0.6%
|
|
| 1982 | 2 |
0.4%
|
|
| 1983 | 2 |
0.4%
|
|
| 1984 | 1 |
0.2%
|
|
| 1986 | 1 |
0.2%
|
|
| 1988 | 3 |
0.6%
|
|
| 1989 | 3 |
0.6%
|
|
| 1990 | 1 |
0.2%
|
|
| 1991 | 3 |
0.6%
|
|
| 1992 | 1 |
0.2%
|
|
| 1994 | 2 |
0.4%
|
|
| 1995 | 1 |
0.2%
|
|
| 1996 | 3 |
0.6%
|
|
| 1997 | 8 |
1.7%
|
|
| 1998 | 8 |
1.7%
|
|
| 1999 | 6 |
1.3%
|
|
| 2000 | 11 |
2.3%
|
|
| 2001 | 2 |
0.4%
|
|
| Sysmiss | 1140 |