Year	Percent
1991	88.062
1992	86.814
1993	89.087
1994	86.79
1995	88.426
1996	89.252
1997	89.415
1998	89.453
1999	89.519
2000	89.669
2001	89.804
2002	89.343
2003	88.866
2004	89.34
2005	89.362
2006	88.519
2007	87.797
2008	88.671
2009	89.11
2010	89.321
2011	89.832
2012	90.038
2013	89.917
2014	89.956
2015	89.809
2016	89.673
2017	89.641
2018	89.61
2019	89.618
2020	89.631
2021	89.669
2022	89.682