| Year | Count |
|---|---|
| 1958 | 18 |
| 1962 | 6 |
| 1975 | 7 |
| 1976 | 9 |
| 1978 | 12 |
| 1979 | 10 |
| 1981 | 6 |
| 1982 | 10 |
| 1983 | 9 |
| 1984 | 6 |
| 1985 | 12 |
| 1986 | 6 |
| 1987 | 14 |
| 1988 | 15 |
| 1989 | 12 |
| 1990 | 8 |
| 1991 | 13 |
| 1992 | 12 |
| 1993 | 18 |
| 1994 | 18 |
| 1995 | 19 |
| 1996 | 31 |
| 1997 | 30 |
| 1998 | 25 |
| 1999 | 32 |
| 2000 | 39 |
| 2001 | 29 |
| 2002 | 27 |
| 2003 | 34 |
| 2004 | 46 |
| 2005 | 43 |
| 2006 | 60 |
| 2007 | 62 |
| 2008 | 48 |
| 2009 | 62 |
| 2010 | 61 |
| 2011 | 67 |
| 2012 | 69 |
| 2013 | 72 |
| 2014 | 68 |
| 2015 | 78 |
| 2016 | 250 |
| 2017 | 258 |
| 2019 | 200 |
| 2020 | 186 |
| 2021 | 220 |
| 2022 | 260 |
| 2023 | 222 |
| 2024 | 208 |