Year	Percent
1991	76.26354
1992	76.28895
1993	76.30747
1994	76.37745
1995	76.42424
1996	76.49308
1997	76.56631
1998	76.634
1999	76.69437
2000	76.99656
2001	77.45428
2002	78.06065
2003	77.9822
2004	80.26882
2005	81.95999
2006	80.42835
2007	78.75154
2008	76.88389
2009	75.29506
2010	73.37016
2011	71.24104
2012	68.87276
2013	67.97579
2014	67.20357
2015	66.49437
2016	65.78608
2017	65.25401
2018	64.67782
2019	64.11399