Year	Number
1961	1
1962	1.046875
1963	1.171875
1964	1.2539184952978055
1965	1.3364779874213837
1966	1.4150943396226416
1967	1.4913657770800628
1968	1.53125
1969	1.588785046728972
1970	1.6490683229813663
1971	1.6414219474497682