Year	Number
1961	98.53207758421689
1962	102.3708085560863
1963	105.6439673102705
1964	109.45104986995996
1965	112.55938395316822
1966	123.41213835167703
1967	126.41977945808384
1968	128.38717334234528
1969	130.42825781354352
1970	132.59595375149618
1971	136.85982312461584
1972	141.15474875751872
1973	145.71769280532354
1974	151.36706831629877
1975	156.40365663223974
1976	160.08935636753264
1977	165.59856218143727
1978	171.01309008375998
1979	174.84213608159325
1980	181.09983704328283
1981	184.73061543343175
1982	187.3520742908945
1983	190.37918101877216
1984	191.39637651549472
1985	194.24134549003412
1986	197.47342204104936
1987	201.3261327787159
1988	203.34965630953735
1989	206.0921933236593
1992	188.66274180063232
1993	190.14568003955168
1994	192.1433417404642
1995	193.53020029358512
1996	195.50745607543246
1997	196.82259136542632
1998	199.4477936886117