Year	Percent
1985	35.2126
1986	72.5885
1987	38.80624
1988	29.56215
1989	30.53407
1990	19.38479
1991	33.4409
1992	36.80468
1993	54.84856
1994	49.16702
1995	49.08317
1996	54.591
1997	46.17398
1998	44.07782
1999	48.2478
2000	35.37097
2001	33.08145
2002	32.66151
2003	37.44978
2004	42.08799
2005	35.38434
2006	40.15501
2007	34.58124
2008	18.16452
2009	29.26261
2010	29.68662
2011	26.19211
2012	30.00694
2013	34.57373
2014	37.031
2015	41.85908
2016	42.2897
2017	45.9995