Year	Number
1971	3460577
1972	3643124
1973	3809701
1974	4057579
1975	4117725
1976	3864720
1977	3915908
1978	3888963
1979	3900006
1980	3918069
1981	3911054
1982	3791497
1983	3803119
1984	3926016
1985	4001236
1986	4043246
1987	4063697
1988	4141825
1989	4169699
1990	4198175
1991	4275891
1992	4289886
1993	4355952
1994	4316446
1995	4300032
1996	4264417
1997	4333313
1998	4480691
1999	4440058
2000	4422962
2001	4414655
2002	4407801
2003	4401887
2004	4298467
2005	4441447
2006	4829313
2007	4760782
2008	4720698
2009	4700123
2010	4699970
2011	4710630
2012	4754127
2013	4804248
2014	4838587
2015	4901509
2016	4936517
2017	4980314