Year	Number
1970	14852
1971	14708
1972	16491
1973	16920
1974	17881
1975	18096
1976	19089
1977	19441
1978	19868
1979	22470
1980	21455
1981	22258
1982	23431
1983	25697
1984	27080
1985	27302
1986	30189
1987	30534
1988	32348
1990	33200
1994	36697
1995	38528
1996	39716
1998	35386
1999	30369
2000	31870
2001	33850
2002	36008
2004	42043
2005	45554
2006	46988
2007	50409
2008	53703
2010	54716
2011	54243
2012	63697
2013	64139
2014	78395
2015	75236
2016	73949
2017	78099
2018	78854
2019	80919
2020	83160