Year	Percent
1995	14.3975
1996	18.69764
1997	17.85261
1998	12.88852
1999	9.59168
2000	10.54772
2001	19.19882
2002	21.17475
2003	22.07826
2004	29.84738
2005	24.75579
2006	25.02327
2007	29.09858
2008	30.32591
2009	19.41559
2010	18.46909
2011	20.10269
2012	21.01042
2013	17.64974
2014	17.49393
2015	18.85193
2016	19.07868
2017	20.99854