Year	Percent
1990	95.578
1991	95.617
1992	95.379
1993	95.193
1994	95.277
1995	94.942
1996	95.014
1997	95.012
1998	94.929
1999	95.119
2000	94.459
2001	94.676
2002	93.964
2003	93.7
2004	93.914
2005	93.774
2006	93.703
2007	93.725
2008	93.581
2009	93.396
2010	92.673
2011	93.019
2012	92.543
2013	92.461
2014	91.905
2015	92.054
2016	91.698
2017	91.672
2018	91.654
2019	91.641
2020	91.629
2021	91.62
2022	91.612
2023	91.605
2024	91.596
2025	91.586
2026	91.574
2027	91.561
2028	91.545
2029	91.526
2030	91.505