| Year | Count |
|---|---|
| 1972 | 7 |
| 1973 | 16 |
| 1974 | 16 |
| 1975 | 23 |
| 1976 | 26 |
| 1977 | 37 |
| 1978 | 60 |
| 1979 | 38 |
| 1980 | 55 |
| 1981 | 28 |
| 1982 | 49 |
| 1983 | 7 |
| 1984 | 25 |
| 1985 | 19 |
| 1986 | 25 |
| 1987 | 32 |
| 1988 | 43 |
| 1989 | 46 |
| 1990 | 51 |
| 1991 | 43 |
| 1992 | 45 |
| 1993 | 63 |
| 1994 | 62 |
| 1995 | 63 |
| 1996 | 54 |
| 1997 | 113 |
| 1998 | 149 |
| 1999 | 135 |
| 2000 | 156 |
| 2001 | 210 |
| 2002 | 276 |
| 2003 | 374 |
| 2004 | 5 |
| 2004 | 576 |
| 2005 | 392 |
| 2006 | 350 |
| 2007 | 424 |
| 2008 | 592 |
| 2009 | 506 |
| 2010 | 412 |
| 2011 | 442 |
| 2012 | 388 |
| 2013 | 339 |
| 2014 | 413 |
| 2015 | 730 |
| 2016 | 806 |
| 2017 | 6 |
| 2017 | 736 |
| 2018 | 844 |
| 2019 | 777 |
| 2020 | 625 |
| 2021 | 718 |
| 2022 | 652 |
| 2023 | 550 |
| 2024 | 519 |