Year	Percent
1990	87.722
1991	87.669
1992	87.649
1993	87.609
1994	87.58
1995	87.34
1996	87.292
1997	87.166
1998	86.919
1999	86.642
2000	86.468
2001	86.281
2002	86.231
2003	85.974
2004	85.745
2005	85.527
2006	85.473
2007	85.489
2008	85.503
2009	85.518
2010	85.539
2011	85.566
2012	85.539
2013	85.549
2014	85.525
2015	85.409
2016	85.28
2017	85.303
2018	85.326
2019	85.349
2020	85.372
2021	85.392
2022	85.412
2023	85.429
2024	85.44
2025	85.444
2026	85.44
2027	85.432
2028	85.417
2029	85.394
2030	85.364