| Year | Count |
|---|---|
| 1971 | 12 |
| 1972 | 37 |
| 1973 | 50 |
| 1974 | 122 |
| 1975 | 131 |
| 1976 | 174 |
| 1977 | 471 |
| 1978 | 339 |
| 1979 | 273 |
| 1980 | 207 |
| 1981 | 156 |
| 1982 | 174 |
| 1983 | 115 |
| 1984 | 124 |
| 1985 | 105 |
| 1986 | 185 |
| 1987 | 173 |
| 1988 | 157 |
| 1989 | 190 |
| 1990 | 175 |
| 1991 | 280 |
| 1992 | 217 |
| 1993 | 228 |
| 1994 | 184 |
| 1995 | 166 |
| 1996 | 122 |
| 1997 | 63 |
| 1998 | 90 |
| 1999 | 67 |
| 2000 | 80 |
| 2001 | 52 |
| 2002 | 58 |
| 2003 | 39 |
| 2004 | 66 |
| 2005 | 34 |
| 2006 | 46 |
| 2007 | 51 |
| 2008 | 70 |
| 2009 | 45 |
| 2010 | 39 |
| 2011 | 32 |
| 2012 | 40 |
| 2013 | 33 |
| 2014 | 47 |
| 2015 | 89 |
| 2016 | 105 |
| 2017 | 81 |
| 2018 | 105 |
| 2019 | 113 |
| 2020 | 95 |
| 2021 | 93 |
| 2022 | 85 |
| 2023 | 124 |
| 2024 | 143 |