Year	Percent
1966	77.13681
1967	78.68704
1968	82.51763
1969	79.7118
1970	66.58911
1971	62.31934
1972	74.33815
1973	74.54131
1974	93.40157
1975	90.207
1976	97.01098
1977	90.57032
1978	81.25658
1979	96.25164
1980	81.30057
1981	69.93824
1982	68.03933
1983	76.36572
1984	84.01997
1985	60.25034
1986	74.8736
1987	75.69354
1988	73.49822
1989	66.1693
1990	69.06701
1991	34.76677
1992	38.50163
1993	43.30882
1994	33.08811
1995	25.19094
1996	32.89175
1997	36.45953
1998	29.63279
1999	25.03917
2000	25.801
2001	20.94823
2002	29.85137
2003	33.7702
2004	41.2707
2005	42.78331
2006	41.33161
2007	41.84342
2008	34.77817
2009	41.06637
2010	37.12089
2011	48.4893
2012	54.81996
2013	50.77604
2014	58.95017
2015	57.92675
2016	49.68364
2017	47.94408