Year	Percent
1995	26.88602
1996	26.71422
1997	28.06472
1998	25.83697
1999	24.81501
2000	23.74391
2001	22.86942
2002	22.68598
2003	21.41881
2004	21.57359
2005	20.334
2006	20.8785
2007	21.70476
2008	21.84551
2009	21.05256
2010	20.79147
2011	21.01664
2012	21.00153
2013	20.41256
2014	19.7394
2015	19.55234
2016	18.56114
2017	19.52249