Year	Percent
1990	84.64
1991	84.647
1992	84.602
1993	84.533
1994	84.353
1995	84.197
1996	84.084
1997	83.949
1998	83.782
1999	83.577
2000	83.334
2001	83.152
2002	82.924
2003	82.656
2004	82.363
2005	82.062
2006	81.898
2007	81.748
2008	81.626
2009	81.554
2010	81.542
2011	81.565
2012	81.629
2013	81.686
2014	81.777
2015	81.85
2016	81.882
2017	82.088
2018	82.277
2019	82.43
2020	82.539
2021	82.632
2022	82.684
2023	82.707
2024	82.722
2025	82.744
2026	82.794
2027	82.851
2028	82.91
2029	82.964
2030	83.01