| Year | Count |
|---|---|
| 1979 | 10 |
| 1985 | 10 |
| 1986 | 7 |
| 1987 | 6 |
| 1988 | 5 |
| 1989 | 14 |
| 1990 | 10 |
| 1991 | 18 |
| 1992 | 35 |
| 1993 | 58 |
| 1994 | 40 |
| 1995 | 78 |
| 1996 | 63 |
| 1997 | 67 |
| 1998 | 105 |
| 1999 | 80 |
| 2000 | 63 |
| 2001 | 64 |
| 2002 | 57 |
| 2003 | 66 |
| 2004 | 63 |
| 2005 | 43 |
| 2006 | 53 |
| 2007 | 58 |
| 2008 | 17 |
| 2009 | 29 |
| 2010 | 7 |
| 2011 | 27 |
| 2015 | 6 |
| 2016 | 14 |
| 2017 | 12 |
| 2018 | 18 |
| 2019 | 10 |