Year	Percent
1992	73.87325
1994	71.98431
1995	69.44772
1996	77.68392
1998	96.00696
1999	94.56827
2000	91.11835
2001	93.62542
2002	92.18615
2003	92.51084
2004	84.99429
2005	85.00283
2006	81.99996
2008	78.51981
2009	84.07171
2010	80.99978
2012	85.36349
2013	86.3781