Year	Percent
1990	83.73
1991	83.925
1992	84.176
1993	84.457
1994	84.748
1995	85.033
1996	84.946
1997	84.883
1998	84.855
1999	84.88
2000	84.561
2001	84.246
2002	83.923
2003	83.592
2004	83.253
2005	82.903
2006	82.548
2007	82.184
2008	81.809
2009	82.064
2010	82.346
2011	82.948
2012	83.57
2013	84.15
2014	84.62
2015	84.956
2016	85.388
2017	85.39
2018	85.4
2019	85.414
2020	85.43
2021	85.447
2022	85.469
2023	85.499
2024	85.539
2025	85.588
2026	85.645
2027	85.713
2028	85.787
2029	85.859
2030	85.923