Year	Percent
1991	92.796
1992	94.388
1993	95.084
1994	94.89
1995	94.415
1996	93.76
1997	86.755
1998	91.771
1999	91.507
2000	89.973
2001	91.776
2002	91.987
2003	94.191
2004	92.114
2005	91.971
2006	91.199
2007	90.935
2008	91.623
2009	91.65
2010	91.193
2011	90.388
2012	90.05
2013	89.648
2014	90.497
2015	91.133
2016	91.282
2017	91.248
2018	91.224
2019	91.197
2020	91.169
2021	91.139
2022	91.111