| Value | Category | Cases | |
|---|---|---|---|
| 1971 | 1 |
0%
|
|
| 1972 | 2 |
0%
|
|
| 1973 | 3 |
0%
|
|
| 1974 | 7 |
0%
|
|
| 1975 | 18 |
0.1%
|
|
| 1976 | 21 |
0.1%
|
|
| 1977 | 49 |
0.2%
|
|
| 1978 | 71 |
0.3%
|
|
| 1979 | 116 |
0.5%
|
|
| 1980 | 185 |
0.8%
|
|
| 1981 | 196 |
0.8%
|
|
| 1982 | 243 |
1%
|
|
| 1983 | 326 |
1.4%
|
|
| 1984 | 355 |
1.5%
|
|
| 1985 | 369 |
1.6%
|
|
| 1986 | 425 |
1.8%
|
|
| 1987 | 433 |
1.8%
|
|
| 1988 | 489 |
2.1%
|
|
| 1989 | 540 |
2.3%
|
|
| 1990 | 552 |
2.3%
|
|
| 1991 | 623 |
2.6%
|
|
| 1992 | 688 |
2.9%
|
|
| 1993 | 644 |
2.7%
|
|
| 1994 | 805 |
3.4%
|
|
| 1995 | 831 |
3.5%
|
|
| 1996 | 929 |
3.9%
|
|
| 1997 | 904 |
3.8%
|
|
| 1998 | 949 |
4%
|
|
| 1999 | 993 |
4.2%
|
|
| 2000 | 1204 |
5.1%
|
|
| 2001 | 1099 |
4.6%
|
|
| 2002 | 1151 |
4.9%
|
|
| 2003 | 1146 |
4.8%
|
|
| 2004 | 1297 |
5.5%
|
|
| 2005 | 1324 |
5.6%
|
|
| 2006 | 1270 |
5.4%
|
|
| 2007 | 1405 |
5.9%
|
|
| 2008 | 1465 |
6.2%
|
|
| 2009 | 525 |
2.2%
|
|
| 9997 | inconsistent | 48 |
0.2%
|
| 9998 | dk | 2 |
0%
|
| 9999 | missing | 13 |
0.1%
|