| Year | Count |
|---|---|
| 1970 | 10 |
| 1972 | 29 |
| 1973 | 15 |
| 1974 | 50 |
| 1975 | 36 |
| 1976 | 53 |
| 1977 | 28 |
| 1978 | 62 |
| 1979 | 59 |
| 1980 | 39 |
| 1981 | 77 |
| 1982 | 44 |
| 1983 | 65 |
| 1984 | 32 |
| 1985 | 96 |
| 1986 | 68 |
| 1987 | 115 |
| 1988 | 100 |
| 1989 | 64 |
| 1990 | 86 |
| 1991 | 125 |
| 1992 | 49 |
| 1993 | 126 |
| 1994 | 95 |
| 1995 | 71 |
| 1996 | 51 |
| 1997 | 58 |
| 1998 | 32 |
| 1999 | 29 |
| 2000 | 34 |
| 2001 | 30 |
| 2002 | 40 |
| 2003 | 12 |
| 2004 | 10 |
| 2005 | 15 |
| 2006 | 24 |
| 2007 | 30 |
| 2008 | 39 |
| 2009 | 36 |
| 2010 | 39 |
| 2012 | 10 |
| 2013 | 16 |
| 2014 | 10 |
| 2015 | 18 |
| 2016 | 10 |
| 2017 | 10 |
| 2018 | 49 |
| 2019 | 15 |
| 2020 | 46 |
| 2021 | 40 |
| 2022 | 33 |
| 2023 | 28 |
| 2024 | 27 |