| Year | Count |
|---|---|
| 1975 | 19 |
| 1977 | 21 |
| 1978 | 124 |
| 1979 | 133 |
| 1980 | 127 |
| 1981 | 231 |
| 1982 | 314 |
| 1983 | 334 |
| 1984 | 426 |
| 1985 | 412 |
| 1986 | 383 |
| 1987 | 462 |
| 1988 | 417 |
| 1989 | 508 |
| 1990 | 344 |
| 1991 | 495 |
| 1992 | 352 |
| 1993 | 235 |
| 1994 | 290 |
| 1995 | 208 |
| 1996 | 186 |
| 1997 | 202 |
| 1998 | 192 |
| 1999 | 202 |
| 2000 | 154 |
| 2001 | 75 |
| 2002 | 75 |
| 2003 | 263 |
| 2004 | 330 |
| 2005 | 364 |
| 2006 | 289 |
| 2007 | 204 |
| 2008 | 286 |
| 2009 | 151 |
| 2010 | 160 |
| 2011 | 148 |
| 2012 | 126 |
| 2013 | 94 |
| 2014 | 96 |
| 2015 | 92 |
| 2016 | 72 |
| 2017 | 37 |
| 2018 | 38 |
| 2019 | 32 |
| 2020 | 46 |
| 2021 | 56 |
| 2022 | 23 |
| 2024 | 7 |