Year	Number
1961	5000
1962	5000
1963	5000
1964	5000
1965	5000
1966	5000
1967	5000
1968	5000
1969	5000
1970	7000
1971	7000
1972	7000
1973	7000
1974	7000
1975	7000
1976	7000
1977	10000
1978	13283
1979	16000
1980	18000
1981	20824
1982	22000
1983	25000
1984	30000
1985	31415
1986	34823
1987	40450
1988	45544
1989	51279
1990	57739
1991	65010
1992	79801
1993	98096
1994	120751
1995	148841
1996	183704
1997	218237
1998	282057
1999	351171
2000	439139
2001	553623
2002	697956