Year	Number
1961	32.96296296296296
1962	39.74264705882353
1963	46.48351648351648
1964	56.8
1965	67.82608695652173
1966	77.98561151079136
1967	83.44086021505376
1968	89.2170818505338
1969	94.39716312056737
1970	97.11267605633803
1971	100.21052631578948
1972	109.7212543554007
1973	114.58333333333333
1974	122.3103448275862
1975	128.79725085910653
1976	133.5836177474403
1977	138.57142857142856
1978	142.66891891891893
1979	146.2289562289562
1980	152.54180602006687
1981	165.1410874053682
1982	160.35123269165823
1983	157.17105263157896
1984	226.07260726072607
1985	177.52890173410404
1986	200.614161849711
1987	187.22772277227725
1988	184.1883116883117
1989	198.0874316939891
1990	340.4017857142857
1991	441.7670682730924
1992	273.3923758182518
1993	323.14410480349346
1994	361.8009478672986
1995	257.93650793650795
1996	261.11111111111114
1997	255.24064171122993
1998	252.6315789473684
1999	286.3157894736842
2000	301.6842105263158
2001	300.52083333333337
2002	305.64102564102564
2003	347.40112994350284
2004	287.08133971291863
2005	298.3783783783784
2006	288.57894736842104
2007	381.82466143977194
2008	366.75585284280936