Year	Percent
1991	66.998
1992	69.793
1993	71.137
1994	72.215
1995	72.687
1996	75.466
1997	76.521
1998	76.281
1999	77.732
2000	77.844
2001	79.204
2002	80.953
2003	81.655
2004	82.91
2005	82.655
2006	82.91
2007	82.083
2008	82.874
2009	83.556
2010	83.813
2011	86.302
2012	87.796
2013	89.224
2014	86.458
2015	86.184
2016	86.716
2017	86.913
2018	87.178
2019	87.464
2020	87.718
2021	87.93
2022	88.177