| Year | Count |
|---|---|
| 1991 | 62 |
| 1992 | 86 |
| 1993 | 106 |
| 1994 | 63 |
| 1995 | 168 |
| 1996 | 325 |
| 1997 | 460 |
| 1998 | 511 |
| 1999 | 501 |
| 2000 | 686 |
| 2001 | 886 |
| 2002 | 1,217 |
| 2003 | 1,690 |
| 2004 | 2,135 |
| 2004 | 16 |
| 2005 | 3,097 |
| 2006 | 3,636 |
| 2007 | 3,951 |
| 2008 | 4,278 |
| 2009 | 4,497 |
| 2010 | 5,740 |
| 2011 | 7,745 |
| 2012 | 8,847 |
| 2013 | 7,820 |
| 2014 | 7,982 |
| 2015 | 8,090 |
| 2016 | 7,964 |
| 2017 | 7,339 |
| 2018 | 6,782 |
| 2019 | 6,285 |
| 2020 | 5,714 |
| 2021 | 6,175 |
| 2022 | 5,420 |
| 2023 | 4,793 |
| 2024 | 4,170 |