Year	Percent
1991	91.417
1992	95.109
1993	95.146
1994	94.829
1995	95.046
1996	95.101
1997	94.942
1998	93.433
1999	93.407
2000	93.245
2001	93.068
2002	90.122
2003	90.043
2004	89.983
2005	89.193
2006	89.253
2007	87.303
2008	87.509
2009	87.399
2010	87.32
2011	87.242
2012	82.704
2013	82.473
2014	86.536
2015	86.442
2016	86.337
2017	86.316
2018	86.253
2019	86.19
2020	86.125
2021	86.064
2022	86.003