Year	Number
1971	1906918
1972	2168559
1973	2397804
1974	2648254
1975	2879948
1976	3111510
1977	3322010
1978	3492091
1979	3692809
1980	3997316
1981	4285889
1982	4335025
1983	4435000
1984	4685353
1985	4828026
1986	4934975
1987	5028026
1988	4895354
1989	4824097
1990	4697277
1991	4559557
1992	4443751
1993	4461857
1994	4580040
1995	4645849
1996	4706541
1997	4567366
1998	4367683
1999	4176780
2000	3958702
2001	3768040
2002	3661759
2003	3645617
2004	3702150
2005	3795981
2006	3864005
2007	3928039
2008	3958781
2009	3994713
2010	3959451
2011	3877799
2012	3793127
2013	3720130
2014	3579411
2015	3396766
2016	3231795
2017	3072037
2018	2893979
2019	2726376
2020	2673796
2021	2671594
2022	2631966