Year	Number
1960	5323
1961	5323
1962	5323
1963	5323
1964	5323
1965	6100
1966	6100
1967	6100
1968	6100
1969	6100
1970	7300
1971	7300
1972	7300
1973	7300
1974	7300
1975	14200
1976	15300
1981	16243
1982	16500
1983	17000
1984	17500
1985	18000
1986	20000
1987	16000
1988	16000
1989	16000
1990	16000
1991	16000
1992	28373
1993	41287
1994	44063
1995	44615
1996	50190
1997	55108
1998	59910
1999	64034
2000	68400
2001	79913
2002	80441
2003	92332
2004	102688
2005	110136
2006	118000
2007	128394
2008	138822
2009	147042
2010	149857
2011	152299
2012	154207
2013	156805
2014	159729
2015	154057
2016	141595
2017	135795
2019	125000
2020	125000
2021	125000