Year	Percent
1995	52.36639
1996	52.40136
1997	52.63348
1998	52.03991
1999	52.36109
2000	53.88398
2001	54.53118
2002	54.44747
2003	55.06807
2004	55.07817
2005	55.63816
2006	55.57916
2007	54.95932
2008	56.00698
2009	58.36606
2010	58.7291
2011	58.12154
2012	57.48977
2013	56.95932
2014	56.05348
2015	56.27836
2016	56.75399
2017	56.39014