Year	Percent
1998	74.52368
1999	83.32708
2000	94.79075
2001	87.79983
2002	81.20173
2003	89.58465
2004	73.87182
2005	77.53218
2006	73.14219
2007	77.34369
2008	76.25258
2009	68.45931
2010	70.35501
2011	80.80533
2012	89.33189
2013	84.28074
2014	78.53039
2015	78.05799