Year	Percent
1977	44.91945
1978	49.4449
1979	63.8064
1980	72.58559
1981	80.46141
1982	89.91722
1983	64.35076
1984	70.78302
1985	77.70088
1986	101.04077
1987	89.90719
1988	71.19246
1989	77.23682
1990	74.12017
1991	74.29223
1992	77.40239
1993	74.46193
1994	71.58207
1995	76.03336
1996	73.74847
1997	70.27283
1998	67.3099
1999	69.08418
2000	60.04412
2001	60.76539
2002	58.24094
2003	62.49699
2004	64.41422
2005	66.7899
2006	70.73547
2007	71.09739
2008	69.58391
2009	57.70679
2010	58.9109
2011	56.15968
2012	57.94751
2013	60.42189
2014	58.009
2015	49.11953
2016	47.0297