| Year | Count |
|---|---|
| 1955 | 8 |
| 1956 | 10 |
| 1960 | 10 |
| 1968 | 7 |
| 1971 | 5 |
| 1972 | 5 |
| 1973 | 9 |
| 1975 | 6 |
| 1976 | 9 |
| 1977 | 20 |
| 1978 | 16 |
| 1980 | 36 |
| 1981 | 12 |
| 1982 | 16 |
| 1983 | 13 |
| 1984 | 15 |
| 1985 | 11 |
| 1986 | 26 |
| 1987 | 18 |
| 1988 | 23 |
| 1989 | 16 |
| 1990 | 24 |
| 1991 | 24 |
| 1992 | 36 |
| 1993 | 29 |
| 1994 | 25 |
| 1995 | 34 |
| 1996 | 22 |
| 1997 | 38 |
| 1998 | 50 |
| 1999 | 51 |
| 2000 | 47 |
| 2001 | 52 |
| 2002 | 72 |
| 2003 | 70 |
| 2004 | 67 |
| 2005 | 65 |
| 2006 | 59 |
| 2007 | 75 |
| 2008 | 77 |
| 2009 | 95 |
| 2010 | 88 |
| 2011 | 72 |
| 2012 | 88 |
| 2013 | 94 |
| 2014 | 81 |
| 2015 | 112 |
| 2016 | 281 |
| 2017 | 257 |
| 2018 | 311 |
| 2019 | 212 |
| 2020 | 199 |
| 2021 | 230 |
| 2022 | 212 |
| 2023 | 246 |
| 2024 | 227 |