Year	Percent
1995	8.10743
1996	15.01346
1997	15.66258
1998	21.15819
1999	11.73226
2000	9.85325
2001	22.44343
2002	20.6452
2003	21.96246
2004	24.21942
2005	27.14087
2006	30.26625
2007	28.36379
2008	29.11695
2009	26.84659
2010	32.93255
2011	33.97611
2012	36.92832
2013	41.20036
2014	43.3759
2015	46.67367
2016	50.02327
2017	52.44966