Year	Number of
1980	11218
1981	10970
1982	11944
1983	11634
1984	10577
1985	10569
1986	10735
1987	11068
1988	10944
1989	10686
1990	11702
1991	11059
1992	11420
1993	12285
1994	11708
1995	11778
1996	12691
1997	13539
1998	14115
1999	14908
2000	15057
2001	14830
2002	14389
2003	15717
2004	14986
2005	15415
2006	16051
2007	16129
2008	17144
2009	17341
2010	18517
2011	19808
2012	21851
2013	23417
2014	24054
2015	23565
2016	25005
2017	25464
2018	25173
2019	25565
2020	22973