Year	Number
1961	33.225806451612904
1962	34.36774193548387
1963	37.4
1964	39.08490566037736
1965	44.0251572327044
1966	50.314465408805034
1967	57.015723270440255
1968	59.74842767295597
1969	62.77463904582549
1970	65.76886940181647
1971	68.75
1972	72.75541795665634
1973	71.42857142857143
1974	71.25748502994011
1975	70.96774193548387
1976	70.40229885057471
1977	70.31471505528778
1978	73.83533548198066
1979	74.86788021139165
1980	80.85239736759637
1981	82.64984227129337
1982	84.17721518987342
1983	82.80254777070064
1984	83.33333333333334
1985	85.01628664495115
1986	86.13861386138613
1987	87.24832214765101
1988	88.5558583106267
1989	86.36082474226804
1990	82.44070127191475
1991	87.87482806052269
1992	94.47730398899587
1993	95.24606628724473
1994	111.13074204946996
1995	118.01548205489092
1996	117.39894551845342
1997	116.87170474516695
1998	114.9704758596735
1999	113.09728429013406
2000	114.17597765363128
2001	117.33958183129056
2002	116.53915553951641
2003	119.52688172043011
2004	125.33858831959873
2005	136.15750915750914
2006	140.73108939558452
2007	148.72667398463227
2008	142.63844797178132