Year	Number
1960	20500
1961	20500
1962	20500
1963	20500
1964	20500
1965	28000
1966	28000
1967	28000
1968	28000
1969	28000
1970	51799
1971	51799
1972	51799
1973	51799
1974	51799
1975	136310
1976	157021
1977	176385
1978	192166
1979	208506
1980	226089
1981	240000
1982	255900
1983	269500
1984	286280
1985	309670
1986	332140
1987	361480
1988	395000
1989	426800
1990	462082
1991	495890
1992	510997
1993	523925
1994	545719
1995	566464
1996	593328
1997	627136
1998	657456
1999	555291
2000	583811
2001	639165
2002	719286
2003	791131
2004	863374
2005	929400
2006	1018072
2007	1079874
2008	1114564
2009	1138729
2010	1161148
2011	1179953
2012	1205768
2013	1221474
2014	1218274
2015	1202466
2016	1171287
2017	1143852
2018	1108200
2019	1071514
2020	1027689
2021	1000228
2022	951138