Year	Number
1970	485000
1971	1057400
1972	1137100
1973	1163500
1974	1214300
1975	1053700
1976	1299800
1977	1454100
1978	1519700
1979	1584000
1980	1483300
1981	1585200
1982	1480800
1983	1578700
1984	1669400
1985	1802700
1986	1828600
1987	2009700
1988	1894600
1989	2118000
1990	2004000
1991	2047500
1992	2391200
1993	2569400
1994	2980400
1995	3453400
1996	3694600
1997	3753600
1998	3698500
1999	4033200
2000	4442967
2001	3967140
2002	3708138
2003	3677879
2004	4968931
2005	4392448
2006	4357151
2007	4662615
2008	4563041
2009	4605452
2010	5084798
2011	5151469
2012	5381980
2013	5565864
2014	5886728
2015	6331198
2016	6866472
2017	6993888
2018	7404373
2019	7068458
2020	1249361
2021	2437207