Year	Number
1960	1200
1961	1200
1962	1200
1963	1200
1964	1200
1965	2000
1966	2000
1967	2000
1968	2000
1969	2000
1970	2500
1971	2500
1972	2500
1973	2500
1974	2500
1975	3358
1976	3550
1977	3600
1978	3900
1979	4600
1980	5210
1981	6039
1982	6939
1983	7430
1984	7900
1985	8300
1986	9440
1987	9816
1988	11800
1989	12500
1990	13600
1991	14350
1992	15170
1993	16338
1994	18189
1995	21130
1996	22602
1997	25073
1998	28999
1999	31314
2000	31858
2001	33739
2002	35060
2003	46199
2004	44507
2005	44091
2006	44287
2007	44849
2008	45162
2009	45162
2010	52966
2011	75825
2012	45565
2013	46000
2014	44400
2015	43000
2016	42000
2017	36833
2018	44135
2019	42507
2020	46966
2021	40046
2022	37746