Year	Number
1960	22772
1961	22772
1962	22772
1963	22772
1964	22772
1965	27700
1966	27700
1967	27700
1968	27700
1969	27700
1970	37100
1971	37100
1972	37100
1973	37100
1974	37100
1975	42500
1976	43550
1977	44625
1978	45700
1979	47400
1980	54200
1981	66013
1982	70381
1983	73500
1984	80770
1985	87686
1986	92065
1987	97333
1988	103521
1989	105483
1990	121388
1991	125834
1992	135504
1993	157774
1994	180724
1995	204350
1996	255049
1997	341622
1998	523529
1999	669113
2000	767411
2001	827195
2002	883108
2003	939013
2004	991239
2005	1243994
2006	1884078
2007	2742059
2008	3446411
2009	3435958
2010	3578463
2011	3608392
2012	3449391
2013	2706787
2014	2709848
2015	3287676
2016	2479802
2017	2603178
2018	2473875
2019	2291464
2020	2607868
2021	2869186
2022	2582154