Year	Number
1971	3823556
1972	4019028
1973	4241657
1974	4442157
1975	4582780
1976	4875179
1977	5067343
1978	5208725
1979	5270298
1980	5297087
1981	5307989
1982	5300387
1983	5319934
1984	5324722
1985	5338731
1986	5361579
1987	5362202
1988	5338012
1989	5284637
1990	5245132
1991	5117897
1992	5010467
1993	4892194
1994	4938465
1995	4825719
1996	4708406
1997	4602243
1998	4490474
1999	4450012
2000	4404331
2001	4473362
2002	4515802
2003	4528300
2004	4505699
2005	4507408
2006	4531571
2007	4553163
2008	4575124
2009	4575921
2010	4626426
2011	4630305
2012	4572722
2013	4594302
2014	4596916
2015	4606017
2016	4589550
2017	4601869
2018	4630438
2019	4640170
2020	4636200
2021	4649000