Year	Percent
1990	30.72913
1991	33.0101
1992	38.84919
1993	39.00896
1994	38.42778
1995	43.49537
1996	43.17642
1997	44.61269
1998	42.48009
1999	43.34091
2000	50.04083
2001	50.28203
2002	46.40183
2003	48.10787
2004	56.52789
2005	59.8333
2006	62.4462
2007	63.96394
2008	61.06246
2009	54.80847
2010	62.93756
2011	67.47782
2012	71.36738
2013	71.10722
2014	76.18126
2015	75.05056
2016	72.05766
2017	72.24171