Year	Number of
1980	9163
1981	9682
1982	8697
1983	8817
1984	8544
1985	8717
1986	9427
1987	9794
1988	10134
1989	10632
1990	9414
1992	9370
1993	9774
1994	14890
1995	9866
1996	11919
1997	13352
1998	14558
1999	15080
2000	15750
2001	17391
2002	20588
2003	24185
2004	20289
2005	21513
2006	23900
2007	19779
2008	17176
2009	19973
2010	16883
2011	15345
2012	14832
2013	20812
2014	18345
2015	16315
2016	16050
2017	16842
2018	16413
2019	16272
2020	12111