Year	Number
1961	8129
1962	8348
1963	8728
1964	10061
1965	11081
1966	12255
1967	9018
1968	9313.52
1969	9856.119999999999
1970	10039.72
1971	8358.08
1972	8597.08
1973	8870.880000000001
1974	8888.04
1975	9216.48
1976	9692.32
1977	9893.32
1978	6607
1979	6714
1980	5911
1981	6895
1982	7014
1983	7092
1984	7194
1985	7316
1986	6417
1987	6441
1988	6491
1989	6552
1990	6010
1991	6035
1992	6069
1993	6104
1994	6140
1995	6177
1996	6248