Year	Number
1970	4587980
1971	4732828
1972	4935148
1973	5154273
1974	5296023
1975	5557560.5
1976	5851768.5
1977	6175013.5
1978	6612566
1979	7064832.5
1980	7446385
1981	7865888
1982	8082115
1983	8375488
1984	8658787
1985	8737327
1986	8780522
1987	8820426
1988	8969404
1989	8934761
1990	8952413
1991	9072905
1992	9055008
1993	9273226
1994	9716846
1995	10201506
1996	10502269
1997	10748619
1998	11292581
1999	11847947
2000	12476890
2001	13344941
2002	14197124
2003	15892617
2004	17238480
2005	18415422
2006	20057748
2007	21284054
2008	23106356
2009	24737516
2010	26320170
2011	27808000
2012	29265736
2013	29599210
2014	30195188
2015	31043346
2016	32231384
2017	33490738
2018	34700568
2019	35691580
2020	37447172