Year	Percent
1990	80.354
1991	80.532
1992	80.746
1993	80.942
1994	81.084
1995	81.307
1996	81.454
1997	81.538
1998	81.652
1999	81.7
2000	81.851
2001	81.84
2002	81.868
2003	81.87
2004	81.884
2005	81.914
2006	81.96
2007	81.917
2008	81.938
2009	81.999
2010	82.107
2011	81.938
2012	81.834
2013	81.777
2014	81.79
2015	81.799
2016	81.818
2017	81.827
2018	81.83
2019	81.823
2020	81.805
2021	81.778
2022	81.742
2023	81.7
2024	81.654
2025	81.607
2026	81.56
2027	81.513
2028	81.467
2029	81.419
2030	81.371