| Year | Count |
|---|---|
| 1957 | 10 |
| 1958 | 70 |
| 1959 | 22 |
| 1960 | 19 |
| 1961 | 10 |
| 1987 | 16 |
| 1989 | 7 |
| 1990 | 22 |
| 1991 | 27 |
| 1992 | 17 |
| 1993 | 48 |
| 1994 | 71 |
| 1995 | 85 |
| 1996 | 99 |
| 1997 | 136 |
| 1998 | 140 |
| 1999 | 122 |
| 2000 | 132 |
| 2001 | 182 |
| 2002 | 178 |
| 2003 | 171 |
| 2004 | 177 |
| 2005 | 323 |
| 2006 | 363 |
| 2007 | 452 |
| 2008 | 535 |
| 2009 | 481 |
| 2010 | 505 |
| 2011 | 642 |
| 2012 | 974 |
| 2013 | 1,495 |
| 2014 | 2,055 |
| 2015 | 2,847 |
| 2016 | 5 |
| 2016 | 3,824 |
| 2017 | 5 |
| 2017 | 6,098 |
| 2018 | 12 |
| 2018 | 6,650 |
| 2019 | 19 |
| 2019 | 7,421 |
| 2020 | 5 |
| 2020 | 6,430 |
| 2021 | 47 |
| 2021 | 7,909 |
| 2022 | 48 |
| 2022 | 8,326 |
| 2023 | 19 |
| 2023 | 7,824 |
| 2024 | 33 |
| 2024 | 7,321 |