Year	Percent
1991	93.17
1992	93.266
1993	93.108
1994	92.956
1995	92.814
1996	92.233
1997	91.867
1998	91.368
1999	90.856
2000	90.655
2001	90.255
2002	89.942
2003	90.049
2004	89.857
2005	89.43
2006	89.211
2007	88.867
2008	88.648
2009	88.444
2010	87.986
2011	87.26
2012	86.296
2013	85.792
2014	85.183
2015	84.953
2016	84.845
2017	84.791
2018	84.479
2019	84.267
2020	83.943
2021	83.566
2022	82.961