| Year | Count |
|---|---|
| 1987 | 6 |
| 1989 | 9 |
| 1991 | 10 |
| 1992 | 13 |
| 1993 | 15 |
| 1994 | 19 |
| 1995 | 15 |
| 1996 | 15 |
| 1997 | 35 |
| 1998 | 23 |
| 1999 | 50 |
| 2000 | 24 |
| 2001 | 43 |
| 2002 | 54 |
| 2003 | 74 |
| 2004 | 74 |
| 2005 | 84 |
| 2006 | 111 |
| 2007 | 128 |
| 2008 | 167 |
| 2009 | 164 |
| 2010 | 228 |
| 2011 | 270 |
| 2012 | 248 |
| 2013 | 274 |
| 2014 | 310 |
| 2015 | 296 |
| 2016 | 957 |
| 2017 | 1,005 |
| 2018 | 1,038 |
| 2019 | 686 |
| 2020 | 632 |
| 2021 | 740 |
| 2022 | 668 |
| 2023 | 672 |
| 2024 | 640 |