| Year | Count |
|---|---|
| 1962 | 15 |
| 1970 | 10 |
| 1975 | 10 |
| 1981 | 12 |
| 1983 | 13 |
| 1985 | 18 |
| 1987 | 6 |
| 1988 | 5 |
| 1991 | 28 |
| 1992 | 20 |
| 1995 | 8 |
| 1996 | 203 |
| 1997 | 142 |
| 1998 | 145 |
| 1999 | 120 |
| 2000 | 86 |
| 2001 | 136 |
| 2002 | 106 |
| 2003 | 30 |
| 2004 | 77 |
| 2005 | 100 |
| 2006 | 72 |
| 2007 | 28 |
| 2008 | 76 |
| 2009 | 14 |
| 2011 | 32 |
| 2015 | 9 |
| 2016 | 15 |
| 2017 | 8 |
| 2018 | 11 |
| 2019 | 9 |
| 2020 | 6 |
| 2021 | 8 |
| 2022 | 5 |
| 2023 | 6 |
| 2024 | 9 |