Year	Percent
1990	80.968
1991	80.999
1992	81.201
1993	81.006
1994	81.168
1995	81.227
1996	81.508
1997	81.771
1998	82.025
1999	82.012
2000	81.954
2001	81.785
2002	81.527
2003	81.125
2004	81.21
2005	81.091
2006	80.996
2007	80.983
2008	81.065
2009	81.295
2010	81.394
2011	81.415
2012	81.536
2013	81.608
2014	81.691
2015	81.803
2016	82.007
2017	82.29
2018	82.584
2019	82.848
2020	83.058
2021	83.274
2022	83.437
2023	83.555
2024	83.651
2025	83.737
2026	83.869
2027	83.998
2028	84.101
2029	84.141
2030	84.099