| Year | Count |
|---|---|
| 1988 | 6 |
| 1989 | 9 |
| 1990 | 6 |
| 1991 | 10 |
| 1992 | 11 |
| 1993 | 43 |
| 1994 | 70 |
| 1995 | 83 |
| 1996 | 84 |
| 1997 | 110 |
| 1998 | 196 |
| 1999 | 211 |
| 2000 | 176 |
| 2001 | 153 |
| 2002 | 155 |
| 2003 | 128 |
| 2004 | 126 |
| 2005 | 156 |
| 2006 | 151 |
| 2007 | 120 |
| 2008 | 137 |
| 2009 | 140 |
| 2010 | 127 |
| 2011 | 125 |
| 2012 | 102 |
| 2013 | 87 |
| 2014 | 92 |
| 2015 | 92 |
| 2016 | 228 |
| 2017 | 222 |
| 2018 | 192 |
| 2019 | 104 |
| 2020 | 116 |
| 2021 | 88 |
| 2022 | 100 |
| 2023 | 110 |
| 2024 | 54 |