Year	Percent
1971	59.55729
1972	54.0008
1999	93.63695
2000	96.29291
2001	95.889
2002	100.62916
2003	95.76442
2004	92.62885
2005	93.10233
2006	91.12002
2007	91.30117
2008	87.50519
2009	95.58293
2010	95.31505
2011	96.87363
2012	96.37824
2013	94.63983
2014	98.51335
2015	98.47158