| Year | Count |
|---|---|
| 1951 | 7 |
| 1962 | 18 |
| 1967 | 5 |
| 1971 | 5 |
| 1972 | 7 |
| 1974 | 5 |
| 1978 | 6 |
| 1979 | 7 |
| 1981 | 15 |
| 1981 | 7 |
| 1982 | 6 |
| 1982 | 5 |
| 1983 | 5 |
| 1983 | 7 |
| 1984 | 14 |
| 1986 | 10 |
| 1987 | 19 |
| 1987 | 5 |
| 1988 | 13 |
| 1989 | 5 |
| 1990 | 19 |
| 1991 | 56 |
| 1991 | 5 |
| 1992 | 28 |
| 1993 | 47 |
| 1994 | 53 |
| 1995 | 60 |
| 1996 | 192 |
| 1997 | 270 |
| 1998 | 376 |
| 1999 | 327 |
| 2000 | 427 |
| 2001 | 445 |
| 2002 | 352 |
| 2003 | 492 |
| 2004 | 802 |
| 2005 | 823 |
| 2006 | 654 |
| 2007 | 711 |
| 2008 | 600 |
| 2009 | 396 |
| 2010 | 286 |
| 2011 | 334 |
| 2012 | 309 |
| 2013 | 223 |
| 2014 | 153 |
| 2015 | 216 |
| 2016 | 165 |
| 2017 | 181 |
| 2018 | 128 |
| 2019 | 136 |
| 2020 | 127 |
| 2021 | 93 |
| 2022 | 175 |
| 2023 | 105 |
| 2024 | 211 |