Year	Percent
1991	81.833
1992	82.047
1993	85.704
1994	86.005
1995	86.382
1996	86.806
1997	87.205
1998	87.389
1999	86.694
2000	86.881
2001	87.253
2002	86.44
2003	87.353
2004	87.581
2005	87.197
2006	87.987
2007	87.686
2008	88.688
2009	89.302
2010	89.036
2011	89.443
2012	90.676
2013	90.59
2014	90.846
2015	90.911
2016	91.075
2017	90.929
2018	91.009
2019	91.137
2020	91.253
2021	91.38
2022	91.496