| Year | Count |
|---|---|
| 1978 | 12 |
| 1979 | 7 |
| 1980 | 24 |
| 1981 | 10 |
| 1982 | 18 |
| 1983 | 12 |
| 1984 | 12 |
| 1985 | 48 |
| 1986 | 56 |
| 1987 | 18 |
| 1988 | 13 |
| 1992 | 22 |
| 1993 | 12 |
| 1994 | 26 |
| 1995 | 27 |
| 1996 | 5 |
| 1997 | 5 |
| 1998 | 26 |
| 1999 | 90 |
| 2000 | 27 |
| 2001 | 10 |
| 2002 | 15 |
| 2003 | 21 |
| 2004 | 98 |
| 2005 | 68 |
| 2006 | 11 |
| 2007 | 19 |
| 2008 | 31 |
| 2009 | 18 |
| 2010 | 21 |
| 2011 | 8 |