Year	Percent
1990	92.662
1991	92.695
1992	92.585
1993	92.472
1994	92.358
1995	92.245
1996	92.131
1997	92.017
1998	91.904
1999	91.79
2000	91.676
2001	91.562
2002	91.447
2003	91.332
2004	91.217
2005	91.103
2006	90.989
2007	90.875
2008	90.759
2009	90.641
2010	90.52
2011	90.396
2012	90.268
2013	90.192
2014	90.061
2015	89.914
2016	89.784
2017	89.719
2018	89.653
2019	89.588
2020	89.525
2021	89.462
2022	89.401
2023	89.342
2024	89.282
2025	89.223
2026	89.164
2027	89.105
2028	89.047
2029	88.991
2030	88.937