Year	Percent
1991	69.105
1992	69.441
1993	68.284
1994	67.391
1995	66.902
1996	69.107
1997	70.052
1998	70.797
1999	71.653
2000	71.816
2001	78.667
2002	75.72
2003	78.939
2004	77.999
2005	80.465
2006	78.728
2007	80.17
2008	82.681
2009	83.243
2010	83.182
2011	83.582
2012	84.127
2013	84.081
2014	84.74
2015	84.002
2016	84.171
2017	84.115
2018	84.219
2019	84.379
2020	84.384
2021	84.419
2022	84.518