Year	Percent
1984	11.72358
1985	10.43662
1986	13.56339
1987	25.56855
1988	42.74066
1989	34.73162
1990	30.50049
1991	25.97054
1992	35.73307
1993	50.6873
1994	56.0376
1995	51.03382
1996	54.06497
1997	60.96123
1998	72.09936
1999	57.47954
2000	49.9654
2001	46.91683
2002	42.51734
2003	39.42027
2004	45.47248
2005	52.45912
2006	56.22925
2007	47.11242
2008	45.83229
2009	43.09612
2010	53.40784
2011	52.50444
2012	52.25794
2013	44.75613
2014	52.25362
2015	55.60488
2016	51.1941
2017	53.69938