| Year | Count |
|---|---|
| 1977 | 38 |
| 1978 | 84 |
| 1979 | 109 |
| 1980 | 126 |
| 1981 | 165 |
| 1982 | 166 |
| 1983 | 134 |
| 1984 | 151 |
| 1985 | 133 |
| 1986 | 199 |
| 1987 | 297 |
| 1988 | 354 |
| 1989 | 371 |
| 1990 | 398 |
| 1991 | 684 |
| 1992 | 954 |
| 1993 | 1,278 |
| 1994 | 904 |
| 1995 | 859 |
| 1996 | 801 |
| 1997 | 837 |
| 1998 | 784 |
| 1999 | 755 |
| 2000 | 740 |
| 2001 | 758 |
| 2002 | 713 |
| 2003 | 692 |
| 2004 | 631 |
| 2005 | 537 |
| 2006 | 546 |
| 2007 | 526 |
| 2008 | 589 |
| 2009 | 504 |
| 2010 | 482 |
| 2011 | 437 |
| 2012 | 427 |
| 2013 | 453 |
| 2014 | 484 |
| 2015 | 676 |
| 2016 | 1,355 |
| 2017 | 1,372 |
| 2018 | 1,203 |
| 2019 | 878 |
| 2020 | 742 |
| 2021 | 778 |
| 2022 | 537 |
| 2023 | 450 |
| 2024 | 353 |