Year	Percent
1990	85.249
1991	85.228
1992	85.175
1993	85.081
1994	84.949
1995	84.76
1996	84.705
1997	84.603
1998	84.465
1999	84.317
2000	84.195
2001	84.193
2002	84.234
2003	84.313
2004	84.382
2005	84.422
2006	84.511
2007	84.498
2008	84.469
2009	84.436
2010	84.401
2011	84.385
2012	85.515
2013	86.558
2014	87.519
2015	87.4
2016	87.273
2017	87.378
2018	87.481
2019	87.579
2020	87.67
2021	87.758
2022	87.842
2023	87.926
2024	88.013
2025	88.103
2026	88.199
2027	88.298
2028	88.401
2029	88.51
2030	88.623