Year	Total
1970	21000000
1971	22442000
1972	22956000
1973	24304000
1974	25084000
1975	27248000
1976	29722000
1977	31476000
1978	31691000
1979	30281000
1980	31267000
1981	32910000
1982	33275000
1983	33020000
1984	32784000
1985	31336000
1986	31712000
1987	30139000
1988	29515000
1989	26458000
1990	22911000
1991	20057000
1992	17612000
1993	16760000
1994	14824000
1995	14446000
1996	13764000
1997	11908000
1998	11150000
1999	11192000
2000	10968000
2001	10780000
2002	10599000
2003	10429000
2004	10377000
2005	9701300
2006	9568500
2007	9232800
2008	9034600
2009	8938500
2010	8625000
2011	8666900
2012	9019500
2013	8605300
2014	8765500
2015	8785200
2016	8235700