| Year | Count |
|---|---|
| 1955 | 5 |
| 1957 | 7 |
| 1958 | 63 |
| 1959 | 22 |
| 1960 | 33 |
| 1961 | 15 |
| 1963 | 14 |
| 1964 | 21 |
| 1966 | 10 |
| 1967 | 6 |
| 1968 | 35 |
| 1969 | 45 |
| 1970 | 61 |
| 1971 | 51 |
| 1972 | 31 |
| 1973 | 53 |
| 1974 | 41 |
| 1975 | 77 |
| 1976 | 49 |
| 1977 | 54 |
| 1978 | 28 |
| 1979 | 7 |
| 1980 | 5 |
| 1981 | 12 |
| 1982 | 17 |
| 1983 | 5 |
| 1986 | 13 |
| 1987 | 6 |
| 1988 | 5 |
| 1989 | 14 |
| 1991 | 15 |
| 1992 | 5 |
| 1996 | 7 |
| 1997 | 12 |
| 1998 | 10 |
| 2000 | 5 |
| 2001 | 6 |
| 2003 | 26 |
| 2004 | 6 |
| 2005 | 44 |
| 2006 | 36 |
| 2007 | 54 |
| 2008 | 78 |
| 2009 | 59 |
| 2010 | 80 |
| 2011 | 76 |
| 2012 | 82 |
| 2013 | 116 |
| 2014 | 90 |
| 2015 | 88 |
| 2016 | 52 |
| 2017 | 28 |
| 2018 | 20 |
| 2019 | 13 |
| 2020 | 8 |
| 2021 | 16 |
| 2022 | 5 |
| 2023 | 10 |
| 2024 | 10 |