| Year | Count |
|---|---|
| 1962 | 5 |
| 1974 | 6 |
| 1977 | 18 |
| 1978 | 10 |
| 1979 | 12 |
| 1980 | 5 |
| 1984 | 5 |
| 1986 | 9 |
| 1988 | 10 |
| 1989 | 6 |
| 1990 | 10 |
| 1991 | 11 |
| 1992 | 13 |
| 1993 | 24 |
| 1994 | 22 |
| 1995 | 9 |
| 1996 | 23 |
| 1997 | 16 |
| 1998 | 14 |
| 1999 | 19 |
| 2000 | 10 |
| 2001 | 10 |
| 2002 | 24 |
| 2003 | 27 |
| 2004 | 45 |
| 2005 | 41 |
| 2006 | 72 |
| 2007 | 97 |
| 2008 | 91 |
| 2009 | 97 |
| 2010 | 143 |
| 2011 | 208 |
| 2012 | 229 |
| 2013 | 309 |
| 2014 | 323 |
| 2015 | 417 |
| 2016 | 1,305 |
| 2017 | 1,239 |
| 2018 | 1,227 |
| 2019 | 884 |
| 2020 | 724 |
| 2021 | 766 |
| 2022 | 860 |
| 2023 | 740 |
| 2024 | 638 |