Year	Percent
1991	76.574
1992	75.267
1993	73.432
1994	71.925
1995	71.322
1996	71.123
1997	71.1
1998	72.227
1999	72.336
2000	72.285
2001	75.344
2002	75.355
2003	75.334
2004	76.183
2005	77.488
2006	77.828
2007	79.108
2008	79.594
2009	80.011
2010	80.007
2011	79.131
2012	78.326
2013	80.821
2014	81.003
2015	81.441
2016	81.821
2017	81.649
2018	81.762
2019	81.969
2020	82.286
2021	82.654
2022	83.093