| Year | Count |
|---|---|
| 1955 | 10 |
| 1965 | 5 |
| 1968 | 5 |
| 1970 | 26 |
| 1971 | 15 |
| 1972 | 21 |
| 1973 | 18 |
| 1974 | 50 |
| 1975 | 12 |
| 1976 | 9 |
| 1977 | 10 |
| 1978 | 37 |
| 1979 | 31 |
| 1980 | 15 |
| 1981 | 15 |
| 1982 | 38 |
| 1983 | 58 |
| 1984 | 44 |
| 1985 | 56 |
| 1986 | 42 |
| 1987 | 41 |
| 1988 | 66 |
| 1989 | 62 |
| 1990 | 65 |
| 1991 | 41 |
| 1992 | 20 |
| 1993 | 59 |
| 1994 | 10 |
| 1995 | 49 |
| 1996 | 78 |
| 1997 | 100 |
| 1998 | 107 |
| 1999 | 64 |
| 2000 | 99 |
| 2001 | 79 |
| 2002 | 38 |
| 2003 | 87 |
| 2004 | 71 |
| 2005 | 48 |
| 2006 | 79 |
| 2007 | 93 |
| 2008 | 118 |
| 2009 | 103 |
| 2010 | 72 |
| 2011 | 53 |
| 2012 | 91 |
| 2013 | 98 |
| 2014 | 50 |
| 2015 | 75 |
| 2016 | 23 |
| 2017 | 55 |
| 2018 | 42 |
| 2019 | 21 |
| 2020 | 17 |
| 2021 | 6 |
| 2022 | 22 |