Year	Number
1960	21738
1961	22137
1962	22282
1963	22258
1964	22100
1965	21882
1966	21781
1967	21837
1968	21943
1969	22093
1970	22295
1971	22558
1972	22692
1973	22776
1974	23113
1975	23752
1976	24737
1977	26113
1978	27924
1979	30219
1980	33039
1981	36223
1982	39570
1983	43056
1984	46647
1985	50303
1986	53968
1987	57581
1988	61061
1989	64592
1990	69060
1991	74237
1992	79364
1993	84585
1994	89943
1995	95463
1996	101159
1997	107050
1998	113099
1999	119338
2000	125779
2001	132507
2002	139448
2003	146370
2004	153261
2005	160130
2006	167034
2007	174047
2008	181289
2009	188812
2010	196623
2011	204701
2012	212870
2013	221312
2014	230292
2015	239772
2016	249715
2017	260155
2018	271245
2019	283022
2020	295764
2021	308837
2022	323274
2023	340184