| Year | Count |
|---|---|
| 1958 | 12 |
| 1963 | 6 |
| 1971 | 6 |
| 1972 | 12 |
| 1973 | 8 |
| 1974 | 9 |
| 1975 | 10 |
| 1976 | 11 |
| 1977 | 20 |
| 1978 | 24 |
| 1979 | 30 |
| 1980 | 34 |
| 1981 | 18 |
| 1982 | 18 |
| 1983 | 12 |
| 1984 | 13 |
| 1985 | 24 |
| 1986 | 19 |
| 1987 | 17 |
| 1988 | 21 |
| 1989 | 23 |
| 1990 | 28 |
| 1991 | 38 |
| 1992 | 39 |
| 1993 | 42 |
| 1994 | 33 |
| 1995 | 48 |
| 1996 | 52 |
| 1997 | 39 |
| 1998 | 57 |
| 1999 | 56 |
| 2000 | 76 |
| 2001 | 93 |
| 2002 | 72 |
| 2003 | 74 |
| 2004 | 75 |
| 2005 | 80 |
| 2006 | 89 |
| 2007 | 96 |
| 2008 | 88 |
| 2009 | 89 |
| 2010 | 89 |
| 2011 | 103 |
| 2012 | 94 |
| 2013 | 118 |
| 2014 | 115 |
| 2015 | 109 |
| 2016 | 339 |
| 2017 | 334 |
| 2018 | 339 |
| 2019 | 258 |
| 2020 | 278 |
| 2021 | 214 |
| 2022 | 298 |
| 2023 | 274 |
| 2024 | 218 |