Year	Percent
1990	87.581
1991	87.94
1992	88.353
1993	88.805
1994	88.999
1995	89.117
1996	89.184
1997	89.123
1998	88.936
1999	88.846
2000	88.687
2001	88.505
2002	88.309
2003	88.183
2004	88.028
2005	87.853
2006	87.664
2007	87.438
2008	87.303
2009	87.317
2010	87.247
2011	87.126
2012	87.055
2013	87.022
2014	86.992
2015	86.955
2016	86.941
2017	86.937
2018	86.93
2019	86.898
2020	86.831
2021	86.698
2022	86.543
2023	86.378
2024	86.219
2025	86.071
2026	85.884
2027	85.71
2028	85.533
2029	85.333
2030	85.1