Year	Percent
1990	89.931
1991	89.933
1992	89.881
1993	89.813
1994	89.76
1995	89.723
1996	89.78
1997	89.833
1998	89.883
1999	89.917
2000	89.928
2001	89.979
2002	90.044
2003	90.006
2004	89.951
2005	89.873
2006	90.349
2007	90.791
2008	91.194
2009	91.554
2010	91.858
2011	91.463
2012	90.979
2013	90.874
2014	90.712
2015	90.493
2016	90.217
2017	90.32
2018	90.433
2019	90.55
2020	90.668
2021	90.784
2022	90.9
2023	91.015
2024	91.127
2025	91.238
2026	91.343
2027	91.446
2028	91.543
2029	91.632
2030	91.713