| Year | Count |
|---|---|
| 1977 | 39 |
| 1979 | 5 |
| 1980 | 5 |
| 1982 | 10 |
| 1983 | 5 |
| 1984 | 5 |
| 1985 | 10 |
| 1986 | 10 |
| 1987 | 15 |
| 1988 | 5 |
| 1989 | 35 |
| 1990 | 127 |
| 1991 | 50 |
| 1992 | 49 |
| 1993 | 90 |
| 1994 | 68 |
| 1995 | 43 |
| 1996 | 15 |
| 1997 | 39 |
| 1998 | 66 |
| 1999 | 12 |
| 2000 | 28 |
| 2001 | 10 |
| 2002 | 23 |
| 2003 | 52 |
| 2004 | 38 |
| 2005 | 22 |
| 2006 | 13 |
| 2007 | 10 |
| 2008 | 10 |
| 2011 | 5 |