Year	Percent
1990	94.152
1991	94.115
1992	94.073
1993	94.452
1994	94.357
1995	94.397
1996	94.442
1997	94.415
1998	94.355
1999	94.419
2000	94.486
2001	94.376
2002	94.305
2003	94.124
2004	93.635
2005	93.358
2006	93.41
2007	93.392
2008	93.363
2009	93.3
2010	93.051
2011	93.087
2012	92.933
2013	92.832
2014	92.694
2015	92.654
2016	92.822
2017	92.755
2018	92.69
2019	92.625
2020	92.562
2021	92.501
2022	92.441
2023	92.382
2024	92.324
2025	92.268
2026	92.212
2027	92.158
2028	92.105
2029	92.054
2030	92.006