Year	Number of
1980	2525
1981	2508
1982	2742
1983	2955
1984	3505
1985	3453
1986	2877
1987	2251
1988	4261
1989	3396
1990	2497
1991	3401
1992	2540
1993	7451
1994	5335
1995	8041
1996	3195
1997	7977
1998	11291
1999	13003
2000	10520
2001	12658
2002	11197
2003	12798
2004	12743
2005	12564
2006	12620
2007	15002
2008	13984
2009	12306
2010	14531
2011	14893
2012	20557
2013	22657
2014	26170
2015	26347
2016	27576
2017	26294
2018	27887
2019	30671
2020	28227