| Year | Count |
|---|---|
| 1973 | 16 |
| 1974 | 11 |
| 1975 | 22 |
| 1976 | 14 |
| 1977 | 10 |
| 1978 | 13 |
| 1979 | 5 |
| 1981 | 10 |
| 1990 | 29 |
| 1991 | 35 |
| 1992 | 21 |
| 1993 | 50 |
| 1994 | 10 |
| 1995 | 24 |
| 1996 | 33 |
| 1997 | 95 |
| 1998 | 108 |
| 1999 | 82 |
| 2000 | 61 |
| 2001 | 71 |
| 2002 | 72 |
| 2003 | 106 |
| 2004 | 45 |
| 2005 | 124 |
| 2006 | 77 |
| 2007 | 73 |
| 2008 | 123 |
| 2009 | 176 |
| 2010 | 143 |
| 2011 | 169 |
| 2012 | 162 |
| 2013 | 110 |
| 2014 | 109 |
| 2015 | 193 |
| 2016 | 149 |
| 2017 | 146 |
| 2018 | 139 |
| 2019 | 149 |
| 2020 | 156 |
| 2021 | 123 |
| 2022 | 114 |
| 2023 | 88 |
| 2024 | 83 |