Year	Percent
1991	91.214
1992	90.993
1993	90.892
1994	90.556
1995	90.221
1996	89.33
1997	88.72
1998	88.675
1999	87.932
2000	86.463
2001	86.386
2002	85.396
2003	84.709
2004	80.555
2005	81.519
2006	80.8
2007	80.282
2008	79.782
2009	80.764
2010	79.846
2011	79.291
2012	79.694
2013	79.288
2014	78.867
2015	78.368
2016	77.924
2017	77.798
2018	77.734
2019	77.668
2020	77.602
2021	77.534
2022	77.475