Year	Percent
1991	91.894
1992	91.674
1993	92.113
1994	92.687
1995	91.902
1996	91.671
1997	91.524
1998	91.709
1999	91.21
2000	90.994
2001	90.77
2002	90.737
2003	90.365
2004	90.267
2005	90.117
2006	89.745
2007	89.197
2008	89.111
2009	88.936
2010	88.777
2011	88.793
2012	88.642
2013	88.619
2014	88.434
2015	88.475
2016	88.232
2017	88.212
2018	88.176
2019	88.14
2020	88.101
2021	88.063
2022	88.023