| Year | Count |
|---|---|
| 1970 | 5 |
| 1972 | 5 |
| 1973 | 9 |
| 1974 | 7 |
| 1975 | 20 |
| 1976 | 6 |
| 1977 | 9 |
| 1978 | 7 |
| 1979 | 22 |
| 1980 | 26 |
| 1981 | 38 |
| 1982 | 28 |
| 1983 | 20 |
| 1984 | 11 |
| 1985 | 40 |
| 1986 | 41 |
| 1987 | 27 |
| 1988 | 55 |
| 1989 | 57 |
| 1990 | 97 |
| 1991 | 97 |
| 1992 | 92 |
| 1993 | 101 |
| 1994 | 79 |
| 1995 | 110 |
| 1996 | 156 |
| 1997 | 174 |
| 1998 | 133 |
| 1999 | 211 |
| 2000 | 235 |
| 2001 | 282 |
| 2002 | 263 |
| 2003 | 352 |
| 2004 | 359 |
| 2005 | 396 |
| 2006 | 448 |
| 2007 | 449 |
| 2008 | 488 |
| 2009 | 464 |
| 2010 | 520 |
| 2011 | 528 |
| 2012 | 633 |
| 2013 | 685 |
| 2014 | 666 |
| 2015 | 785 |
| 2016 | 1,027 |
| 2017 | 1,039 |
| 2018 | 939 |
| 2019 | 932 |
| 2020 | 596 |
| 2021 | 727 |
| 2022 | 797 |
| 2023 | 766 |
| 2024 | 950 |