Year	Percent
1996	12.08962
1997	18.2832
1998	18.73332
1999	15.05733
2000	14.72575
2001	12.17134
2002	12.88135
2003	14.67291
2004	16.35751
2005	18.4854
2006	19.57105
2007	20.5667
2008	20.4461
2009	17.68531
2010	18.19547
2011	18.27995
2012	18.64493
2013	18.39747
2014	19.81972
2015	19.50458
2016	19.29555