| Year | Count |
|---|---|
| 1955 | 15 |
| 1956 | 5 |
| 1958 | 10 |
| 1960 | 14 |
| 1962 | 12 |
| 1964 | 10 |
| 1965 | 10 |
| 1966 | 14 |
| 1967 | 15 |
| 1970 | 8 |
| 1977 | 5 |
| 1981 | 5 |
| 1986 | 8 |
| 1987 | 5 |
| 1989 | 7 |
| 1991 | 7 |
| 1993 | 5 |
| 1995 | 5 |
| 1997 | 12 |
| 2000 | 8 |
| 2001 | 40 |
| 2002 | 14 |
| 2003 | 10 |
| 2004 | 6 |
| 2005 | 32 |
| 2006 | 20 |
| 2007 | 18 |
| 2008 | 47 |
| 2009 | 21 |
| 2010 | 40 |
| 2011 | 27 |
| 2012 | 28 |
| 2013 | 35 |
| 2014 | 25 |
| 2015 | 25 |
| 2016 | 29 |
| 2017 | 57 |
| 2018 | 15 |
| 2019 | 13 |
| 2022 | 5 |