Year	Number
1975	13489
1976	13105
1977	12265
1978	12674
1979	12681
1980	15494
1981	15640
1982	15263
1983	15970
1984	16728
1985	16947
1986	17997
1987	19129
1988	18755
1989	18553
1990	18340
1991	18818
1992	18709
1993	19290
1994	19489
1995	20579
1996	21606
1997	21962
1998	22569
1999	22841
2000	24083
2001	24213
2002	23513
2003	25168
2004	22086
2005	22188
2006	26111
2007	26430
2008	25697
2009	24690
2010	24374
2011	24525
2012	24107
2013	25082
2014	25324
2015	23464
2016	22987
2017	22585
2018	22048
2019	21466
2020	22046
2021	24040
2022	21202