Year	Percent
1991	92.565
1992	92.836
1993	93.104
1994	91.842
1995	90.489
1996	90.995
1997	89.788
1998	89.486
1999	89.94
2000	88.112
2001	86.471
2002	87.755
2003	89.017
2004	90.759
2005	90.561
2006	90.42
2007	90.071
2008	90.112
2009	90.843
2010	90.9
2011	91.18
2012	91.034
2013	91.367
2014	91.188
2015	90.751
2016	90.563
2017	91.05
2018	90.731
2019	90.479
2020	90.318
2021	90.467
2022	90.504