Year	Percent
1990	94.147
1991	94.434
1992	94.115
1993	94.025
1994	93.793
1995	93.624
1996	93.381
1997	92.774
1998	92.936
1999	92.93
2000	92.396
2001	92.402
2002	92.654
2003	92.341
2004	92.407
2005	92.52
2006	92.904
2007	92.881
2008	93.191
2009	92.486
2010	92.663
2011	92.428
2012	92.144
2013	91.142
2014	91.63
2015	91.761
2016	91.925
2017	91.868
2018	91.804
2019	91.731
2020	91.652
2021	91.563
2022	91.468
2023	91.372
2024	91.281
2025	91.198
2026	91.122
2027	91.054
2028	90.994
2029	90.941
2030	90.895