Year	Number
1960	17339
1961	17339
1962	17339
1963	17339
1964	17339
1965	27000
1966	27000
1967	27000
1968	27000
1969	27000
1970	33300
1971	33300
1972	33300
1973	33300
1974	33300
1975	42300
1976	43200
1977	43500
1978	43984
1979	44286
1980	45355
1981	45874
1982	48282
1983	51859
1984	54973
1985	57642
1986	58150
1987	58745
1988	59000
1989	60000
1990	62000
1991	63600
1992	64000
1993	64000
1994	64000
1995	75000
1996	99000
1997	112544
1998	162225
1999	251420
2000	386775
2001	448000
2002	671842
2003	936756
2004	1028899
2005	570000
2006	499000
2007	345194
2008	366200
2009	370423
2010	544984
2011	483617
2012	424586
2013	415571
2014	415106
2015	118954
2016	136472
2017	143280
2018	136923
2019	137842
2020	129408
2021	131485
2022	155802