Year	Percent
1981	3.66119
1982	4.93784
1983	10.93348
1984	10.75241
1985	12.9204
1986	15.38722
1987	20.71966
1988	19.17783
1989	20.81054
1990	23.50056
1991	20.19484
1992	20.75406
1993	22.20256
1994	23.90025
1995	22.57208
1996	21.67034
1997	21.37375
1998	25.26208
1999	33.46415
2000	43.34233
2001	48.30643
2002	63.95714
2003	53.84277
2004	44.44545
2005	27.19168
2006	26.38354
2007	25.64341
2008	24.4847
2009	25.91917
2010	26.29443
2011	23.21415
2012	49.20919
2013	27.78455
2014	26.79045