Year	Percent
2001	81.45994
2002	82.85318
2003	81.71674
2004	80.26492
2005	80.39563
2006	79.40345
2007	79.27504
2008	78.56192
2009	78.99152
2010	78.86851
2011	81.0631
2012	80.59482
2013	80.69005
2014	80.65985
2015	79.10334
2016	79.07284