Year	Number
1960	18081445
1961	18414469
1962	18702026
1963	18972268
1964	19204966
1965	19418425
1966	19619691
1967	19593877
1968	19475621
1969	19318970
1970	19117521
1971	18986144
1972	18866224
1973	18712057
1974	18532955
1975	18334334
1976	18024996
1977	17668459
1978	17289379
1979	16897538
1980	16499970
1981	16106161
1982	15706552
1983	15288478
1984	14828582
1985	14332610
1986	13732808
1987	13084611
1988	12445873
1989	11822906
1990	11212890
1991	10836049
1992	10578257
1993	10321655
1994	10065774
1995	9812686
1996	9714056
1997	9693908
1998	9653050
1999	9610494
2000	9579783
2001	9502455
2002	9386489
2003	9266208
2004	9134717
2005	8988830
2006	8947521
2007	8942697
2008	8960824
2009	8956768
2010	8951455
2011	9027046
2012	9110771
2013	9188649
2014	9283086
2015	9369405
2016	9443539
2017	9500413
2018	9564386
2019	9612727
2020	9634283
2021	9621887
2022	9597146
2023	9589588