Year	Percent
1991	91.563
1992	92.13
1993	91.86
1994	91.561
1995	91.039
1996	90.521
1997	90.203
1998	89.763
1999	88.801
2000	88.292
2001	87.647
2002	86.919
2003	86.411
2004	85.457
2005	84.269
2006	84.002
2007	83.493
2008	83.259
2009	82.955
2010	81.903
2011	81.108
2012	80.925
2013	79.479
2014	78.486
2015	77.258
2016	76.463
2017	75.782
2018	75.023
2019	74.391
2020	73.766
2021	73.145
2022	72.546