| Year | Count |
|---|---|
| 1990 | 5 |
| 1991 | 10 |
| 1992 | 6 |
| 1992 | 5 |
| 1994 | 5 |
| 1995 | 5 |
| 1996 | 22 |
| 1997 | 18 |
| 1998 | 6 |
| 1999 | 37 |
| 2000 | 18 |
| 2001 | 37 |
| 2002 | 52 |
| 2003 | 125 |
| 2004 | 136 |
| 2005 | 140 |
| 2006 | 182 |
| 2007 | 164 |
| 2008 | 275 |
| 2009 | 200 |
| 2010 | 240 |
| 2011 | 318 |
| 2012 | 233 |
| 2013 | 208 |
| 2014 | 195 |
| 2015 | 124 |
| 2016 | 100 |
| 2017 | 86 |
| 2018 | 76 |
| 2019 | 24 |
| 2020 | 11 |
| 2021 | 20 |
| 2023 | 16 |