Year	Percent
1990	84.865
1991	84.895
1992	84.963
1993	85.047
1994	85.102
1995	85.112
1996	85.1
1997	85.018
1998	84.906
1999	84.806
2000	84.7
2001	84.609
2002	84.532
2003	84.462
2004	84.416
2005	84.406
2006	84.377
2007	84.363
2008	84.358
2009	84.314
2010	84.299
2011	84.293
2012	84.281
2013	84.296
2014	84.312
2015	84.421
2016	84.417
2017	84.501
2018	84.593
2019	84.673
2020	84.729
2021	84.763
2022	84.771
2023	84.761
2024	84.753
2025	84.758
2026	84.775
2027	84.801
2028	84.83
2029	84.848
2030	84.846
