Year	Percent
2000	62.15
2001	62.06
2002	60.13
2003	61.86
2004	61.9
2005	64.24
2006	64.58
2007	64.79
2008	68.53
2009	69.66
2010	70.71
2011	71.19
2012	71.7
2013	71.48
2014	71.91
2015	70.55
2016	71.08
2017	71.46