| Value | Category | Cases | |
|---|---|---|---|
| 1978 | 2 |
0.1%
|
|
| 1979 | 2 |
0.1%
|
|
| 1980 | 5 |
0.1%
|
|
| 1981 | 4 |
0.1%
|
|
| 1982 | 15 |
0.4%
|
|
| 1983 | 8 |
0.2%
|
|
| 1984 | 15 |
0.4%
|
|
| 1985 | 21 |
0.6%
|
|
| 1986 | 16 |
0.4%
|
|
| 1987 | 15 |
0.4%
|
|
| 1988 | 23 |
0.6%
|
|
| 1989 | 31 |
0.8%
|
|
| 1990 | 38 |
1%
|
|
| 1991 | 47 |
1.2%
|
|
| 1992 | 61 |
1.6%
|
|
| 1993 | 55 |
1.5%
|
|
| 1994 | 71 |
1.9%
|
|
| 1995 | 87 |
2.3%
|
|
| 1996 | 81 |
2.2%
|
|
| 1997 | 85 |
2.3%
|
|
| 1998 | 99 |
2.6%
|
|
| 1999 | 108 |
2.9%
|
|
| 2000 | 155 |
4.1%
|
|
| 2001 | 115 |
3.1%
|
|
| 2002 | 153 |
4.1%
|
|
| 2003 | 190 |
5%
|
|
| 2004 | 228 |
6.1%
|
|
| 2005 | 189 |
5%
|
|
| 2006 | 241 |
6.4%
|
|
| 2007 | 286 |
7.6%
|
|
| 2008 | 402 |
10.7%
|
|
| 2009 | 459 |
12.2%
|
|
| 2010 | 453 |
12%
|
|
| 2011 | 2 |
0.1%
|
|
| 9997 | inconsistent | 0 |
0%
|
| 9998 | dk | 1 |
0%
|
| 10001 | .Z | 14991 |