Year	Percent
1995	15.89954
1996	19.17034
1997	21.33397
1998	25.97014
1999	22.4023
2000	24.72434
2001	28.18177
2002	28.15828
2003	30.17111
2004	33.03493
2005	35.14406
2006	39.22785
2007	41.53843
2008	35.09006
2009	21.98608
2010	19.31859
2011	25.17279
2012	26.17478
2013	24.28719
2014	22.67439
2015	22.23429
2016	19.57901
2017	21.46895