Year	Percent
1990	93.588
1991	93.339
1992	92.714
1993	91.802
1994	91.07
1995	89.806
1996	89.502
1997	89.576
1998	89.993
1999	90.384
2000	90.468
2001	90.138
2002	89.548
2003	88.882
2004	88.273
2005	87.956
2006	87.876
2007	88.079
2008	88.395
2009	88.684
2010	88.785
2011	88.828
2012	88.7
2013	88.501
2014	88.243
2015	87.987
2016	87.702
2017	87.64
2018	87.575
2019	87.499
2020	87.41
2021	87.32
2022	87.22
2023	87.122
2024	87.038
2025	86.976
2026	86.94
2027	86.924
2028	86.92
2029	86.918
2030	86.912