Year	Percent
1995	53.01605
1996	52.48464
1997	54.91887
1998	50.30158
1999	51.74682
2000	56.57594
2001	59.30955
2002	58.13412
2003	58.84807
2004	59.20298
2005	60.31766
2006	63.10206
2007	63.16391
2008	63.61977
2009	50.27791
2010	53.27267
2011	57.71815
2012	58.6985
2013	59.7052
2014	63.59149
2015	67.85378
2016	69.59958
2017	74.26967