Year	Number
1961	33574
1962	35669
1963	36614
1964	37956
1965	39924
1966	42451
1967	45932
1968	48803
1969	51517
1970	54238
1971	52275
1972	53617
1973	50732
1974	51225
1975	51742
1976	52914
1977	53968
1978	49468
1979	49701
1980	50909
1981	51471
1982	52240
1983	52040
1984	52469
1985	52522
1986	52713
1987	52666
1988	47369
1989	47649
1990	47712
1991	49435
1992	49455
1993	49931
1994	50238
1995	50988
1996	51037
1997	54285