Year	Number
1970	4133360
1971	4242941.5
1972	4434818.5
1973	4614714.5
1974	4774185
1975	5066326.5
1976	5336703
1977	5581601.5
1978	5898465.5
1979	6243537
1980	6648096.5
1981	7086947.5
1982	7482888.5
1983	7943148
1984	8574489
1985	9137168
1986	9516915
1987	9722096
1988	9873167
1989	9753950
1990	10048149
1991	10437475
1992	10507787
1993	10869973
1994	11448574
1995	12197638
1996	12769335
1997	13041257
1998	13819187
1999	14393451
2000	14928213
2001	15948920
2002	16810566
2003	17633666
2004	18969636
2005	20048074
2006	21493806
2007	22702080
2008	24204150
2009	25572434
2010	26857468
2011	27985482
2012	29398648
2013	30842224
2014	32266842
2015	33121706
2016	34156860
2017	35238644
2018	36322412
2019	37550216
2020	39392800