Year	Percent
1990	94.045
1991	94.136
1992	94.099
1993	94.072
1994	93.884
1995	93.848
1996	93.865
1997	93.776
1998	93.663
1999	93.435
2000	93.334
2001	93.343
2002	93.226
2003	93.121
2004	93.127
2005	93.084
2006	92.994
2007	92.995
2008	93.023
2009	93.04
2010	92.715
2011	92.942
2012	92.842
2013	92.77
2014	92.664
2015	92.581
2016	92.494
2017	92.472
2018	92.457
2019	92.447
2020	92.441
2021	92.438
2022	92.44
2023	92.442
2024	92.442
2025	92.437
2026	92.429
2027	92.415
2028	92.396
2029	92.374
2030	92.349