Year	Percent
1984	31.3047
1985	24.74184
1986	23.44542
1987	23.00667
1988	18.70685
1989	20.55184
1990	30.88266
1991	26.0316
1992	25.27553
1993	28.29502
1994	28.94882
1995	28.88198
1998	35.16215
1999	40.15258
2000	42.83183
2001	44.42358
2002	48.69151
2003	46.76059
2004	57.87242
2005	64.56992
2006	68.4191
2007	67.76488
2008	59.68936
2009	67.09603
2010	68.9094
2012	68.23882
2013	68.78907
2014	70.13059