Year	Number
1971	1056787
1972	1468340
1973	1605769
1974	1766906
1975	1989567
1976	2183137
1977	2356878
1985	3107548
1988	3861050
1990	4696606
1991	5084832
1992	5619057
1993	6322988
1994	7059037
1995	7652829
1997	8776792
1999	9726948
2000	9954767
2001	9933471
2002	9916372
2003	9704392
2004	9440807
2005	9066410
2006	8805028
2007	8323213
2008	8187132
2009	7877610
2010	7347083
2011	7237005
2012	7118357
2013	5868528
2014	5794537
2015	5712478
2016	5713648
2017	5684238
2020	6122264