Year	Percent
1991	87.186
1992	88.09
1993	88.51
1994	88.66
1995	89.094
1996	89.581
1997	89.871
1998	89.864
1999	90.339
2000	90.894
2001	90.854
2002	91.334
2003	91.393
2004	91.627
2005	91.865
2006	92.078
2007	91.811
2008	92.025
2009	92.152
2010	91.66
2011	92.047
2012	92.086
2013	92.032
2014	92.051
2015	92.337
2016	92.558
2017	92.193
2018	92.384
2019	92.571
2020	92.711
2021	92.85
2022	92.987