Year	Percent
1990	88.17
1991	88.217
1992	88.26
1993	88.298
1994	88.326
1995	88.338
1996	88.327
1997	88.298
1998	88.254
1999	88.206
2000	88.159
2001	88.118
2002	88.081
2003	88.048
2004	88.02
2005	87.996
2006	87.979
2007	87.967
2008	87.976
2009	87.945
2010	91.527
2011	89.526
2012	88.846
2013	87.698
2014	87.874
2015	85.751
2016	85.791
2017	85.93
2018	86.075
2019	86.216
2020	86.345
2021	86.465
2022	86.574
2023	86.673
2024	86.765
2025	86.852
2026	86.932
2027	87.005
2028	87.072
2029	87.131
2030	87.184