Year	Percent
1991	74.731
1992	74.737
1993	74.443
1994	74.117
1995	73.958
1996	74.348
1997	74.949
1998	75.281
1999	75.973
2000	76.529
2001	77.403
2002	77.184
2003	76.812
2004	76.566
2005	75.973
2006	76.273
2007	76.634
2008	78.166
2009	79.909
2010	81.346
2011	83.009
2012	83.015
2013	83.151
2014	83.122
2015	83.134
2016	83.164
2017	83.352
2018	83.543
2019	83.736
2020	83.93
2021	84.128
2022	84.32