Year	Percent
1991	64.506
1992	65.238
1993	66.523
1994	67.59
1995	68.412
1996	69.064
1997	69.731
1998	71.259
1999	72.087
2000	72.881
2001	73.946
2002	75.286
2003	75.739
2004	76.852
2005	78.028
2006	78.306
2007	78.101
2008	79.206
2009	80.533
2010	81.134
2011	81.77
2012	81.759
2013	81.931
2014	82.244
2015	82.004
2016	82.411
2017	82.436
2018	82.839
2019	83.016
2020	83.185
2021	83.314
2022	83.516