| Year | Count |
|---|---|
| 1967 | 9 |
| 1968 | 6 |
| 1969 | 9 |
| 1970 | 10 |
| 1971 | 22 |
| 1972 | 17 |
| 1973 | 14 |
| 1974 | 19 |
| 1975 | 35 |
| 1976 | 17 |
| 1977 | 40 |
| 1978 | 28 |
| 1979 | 27 |
| 1980 | 6 |
| 1982 | 5 |
| 1986 | 5 |
| 1987 | 7 |
| 1988 | 6 |
| 1993 | 5 |
| 1996 | 5 |
| 1997 | 5 |
| 1998 | 6 |
| 2000 | 12 |
| 2001 | 8 |
| 2002 | 17 |
| 2004 | 12 |
| 2005 | 16 |
| 2006 | 14 |
| 2007 | 18 |
| 2008 | 22 |
| 2009 | 9 |
| 2012 | 5 |
| 2013 | 16 |
| 2014 | 31 |
| 2015 | 12 |
| 2016 | 12 |
| 2017 | 26 |
| 2018 | 30 |
| 2021 | 16 |
| 2022 | 6 |
| 2023 | 22 |
| 2024 | 23 |