Year	Percent
1982	51.97091
1983	59.00084
1984	64.10202
1985	70.10409
1986	57.45541
1987	66.24062
1988	68.41279
1989	71.60957
1990	71.56132
1991	79.61961
1992	87.6775
1993	83.3816
1994	38.44447
1995	46.24982
1996	44.01603
1997	39.23278
1998	41.56129
1999	52.15703
2000	63.56412
2001	72.74955
2002	70.75994
2003	70.11573
2004	70.25107
2005	70.42376
2006	66.91144
2007	65.89716
2008	55.87298
2009	49.29322
2010	59.10892
2011	55.71483
2012	52.62525
2013	53.26696
2014	54.62316
2015	53.42258
2016	51.61541
2017	46.75912