Year	Percent
1991	89.465
1992	89.424
1993	89.344
1994	89.426
1995	88.488
1996	87.896
1997	87.697
1998	87.927
1999	89.09
2000	89.017
2001	88.47
2002	88.292
2003	89.468
2004	90.283
2005	90.693
2006	91.302
2007	91.241
2008	90.411
2009	90.14
2010	89.597
2011	89.228
2012	88.723
2013	88.08
2014	88.608
2015	88.501
2016	88.938
2017	89.431
2018	89.554
2019	90.031
2020	90.126
2021	90.297
2022	90.033