Year	Percent
1990	89.504
1991	89.619
1992	89.745
1993	89.867
1994	89.961
1995	90.016
1996	90.029
1997	90.014
1998	89.981
1999	89.945
2000	89.916
2001	89.874
2002	89.828
2003	89.776
2004	89.707
2005	89.668
2006	89.637
2007	89.608
2008	89.581
2009	89.55
2010	89.532
2011	89.524
2012	89.523
2013	89.529
2014	89.541
2015	89.557
2016	89.581
2017	89.61
2018	89.639
2019	89.667
2020	89.693
2021	89.72
2022	89.743
2023	89.762
2024	89.774
2025	89.779
2026	89.783
2027	89.78
2028	89.767
2029	89.734
2030	89.681