Year	Number
1970	405435
1971	408697
1972	413203
1973	422652
1974	440304
1975	454194
1976	445397
1977	441907
1978	442117
1979	441617
1980	510080
1981	528140
1982	594167
1983	614615
1984	656521
1985	715518
1986	761601
1987	770615
1988	811256
1998	2683111
1999	3665865
2000	3829421
2001	3904915
2002	3905207
2003	3902011
2004	3919748
2005	3884317
2006	3872929
2007	3897005
2008	3963715
2009	4106048
2010	4213136
2011	4279426
2012	4346391
2013	4406046
2014	4450741
2015	4501734
2016	4583002
2017	4612663