Year	Number of
1980	14442
1981	13876
1982	13808
1983	13357
1984	12563
1985	12423
1986	13090
1987	13286
1988	13501
1989	13307
1990	10969
1991	10821
1992	10920
1993	10425
1994	10519
1995	11310
1996	13944
1997	16109
1998	20623
1999	24979
2000	25843
2001	26224
2002	27546
2003	35145
2004	28432
2005	28629
2006	26619
2007	26710
2008	23140
2009	24905
2010	23399
2011	25074
2012	18006
2013	18958
2014	15244
2015	14006
2016	12322
2017	12449
2018	12832
2019	12501
2020	9603