Year	Number
1970	7735614
1971	7947058
1972	8230755
1973	8601594
1974	8780946
1975	9083941
1976	9379595
1977	9760536
1978	10200000
1979	10800000
1980	11700000
1981	11800000
1982	12400000
1983	13100000
1984	13700000
1985	14000000
1986	14300000
1987	14700000
1988	15200000
1989	15600000
1990	15700000
1991	16900000
1992	17800000
1993	18700000
1994	20000000
1995	21600000
1996	22900000
1997	24000000
1998	26200000
1999	27700000
2000	29400000
2001	31200000
2002	33200000
2003	35600000
2004	37100000
2005	38700000
2006	41000000
2007	42900000
2008	45000000
2009	47900000
2010	50800000
2011	53300000
2012	56100000
2013	58200000
2014	59700000
2015	61600000
2016	64300000
2017	65500000
2018	67200000