| Year | Count |
|---|---|
| 1970 | 5 |
| 1976 | 10 |
| 1977 | 15 |
| 1979 | 22 |
| 1981 | 6 |
| 1982 | 15 |
| 1984 | 7 |
| 1985 | 7 |
| 1986 | 18 |
| 1987 | 14 |
| 1988 | 10 |
| 1989 | 22 |
| 1990 | 32 |
| 1991 | 7 |
| 1992 | 19 |
| 1993 | 5 |
| 1994 | 21 |
| 1995 | 29 |
| 1996 | 33 |
| 1997 | 30 |
| 1998 | 42 |
| 1999 | 20 |
| 2000 | 41 |
| 2001 | 51 |
| 2002 | 23 |
| 2003 | 64 |
| 2004 | 43 |
| 2005 | 50 |
| 2006 | 36 |
| 2007 | 62 |
| 2008 | 36 |
| 2009 | 36 |
| 2010 | 8 |
| 2011 | 18 |
| 2012 | 38 |
| 2013 | 32 |
| 2014 | 39 |
| 2015 | 120 |
| 2016 | 119 |
| 2017 | 217 |
| 2018 | 130 |
| 2019 | 162 |
| 2020 | 214 |
| 2021 | 227 |
| 2022 | 202 |
| 2023 | 212 |
| 2024 | 196 |