Year	Percent
1995	67.0071
1996	59.92015
1997	66.74244
1998	69.40073
1999	73.10593
2000	71.32372
2001	64.97933
2002	63.60695
2003	62.16609
2004	63.7408
2005	64.23062
2006	64.88469
2007	66.08716
2008	70.04582
2009	69.16232
2010	71.39849
2011	70.64785
2012	70.78793
2013	71.40437
2014	71.47675
2015	71.26325
2016	71.05706
2017	71.19538