| Value | Category | Cases | |
|---|---|---|---|
| 1978 | 2 |
0.1%
|
|
| 1979 | 2 |
0.1%
|
|
| 1980 | 6 |
0.3%
|
|
| 1981 | 4 |
0.2%
|
|
| 1982 | 15 |
0.8%
|
|
| 1983 | 8 |
0.4%
|
|
| 1984 | 15 |
0.8%
|
|
| 1985 | 21 |
1.1%
|
|
| 1986 | 16 |
0.8%
|
|
| 1987 | 16 |
0.8%
|
|
| 1988 | 26 |
1.3%
|
|
| 1989 | 33 |
1.7%
|
|
| 1990 | 40 |
2%
|
|
| 1991 | 49 |
2.5%
|
|
| 1992 | 65 |
3.3%
|
|
| 1993 | 60 |
3%
|
|
| 1994 | 72 |
3.6%
|
|
| 1995 | 92 |
4.6%
|
|
| 1996 | 85 |
4.3%
|
|
| 1997 | 93 |
4.7%
|
|
| 1998 | 117 |
5.9%
|
|
| 1999 | 121 |
6.1%
|
|
| 2000 | 171 |
8.6%
|
|
| 2001 | 132 |
6.7%
|
|
| 2002 | 170 |
8.6%
|
|
| 2003 | 240 |
12.1%
|
|
| 2004 | 311 |
15.7%
|
|
| 9997 | inconsistent | 0 |
0%
|
| 9998 | don't know | 1 |
0.1%
|
| 10001 | .Z | 16771 |