Year	Number
1961	295
1962	280
1963	229.99999999999997
1964	229.99999999999997
1965	445
1966	475
1967	295
1968	325
1969	340
1970	350
1971	360
1972	370
1973	370
1974	375
1975	375
1976	375
1977	385
1978	400