Year	Percent
1990	85.064
1991	85.077
1992	85.024
1993	85.056
1994	84.606
1995	84.228
1996	83.663
1997	83.035
1998	82.673
1999	82.25
2000	81.895
2001	81.83
2002	81.755
2003	81.6
2004	81.521
2005	81.499
2006	81.617
2007	81.535
2008	81.408
2009	81.223
2010	80.973
2011	80.66
2012	80.664
2013	80.63
2014	80.498
2015	80.296
2016	80.059
2017	80.054
2018	80.036
2019	80.01
2020	79.978
2021	79.942
2022	79.901
2023	79.86
2024	79.824
2025	79.796
2026	79.776
2027	79.764
2028	79.759
2029	79.762
2030	79.774