Year	Percent
1990	84.989
1991	85.351
1992	85.485
1993	85.565
1994	85.561
1995	85.43
1996	86.182
1997	86.342
1998	86.486
1999	86.301
2000	86.492
2001	85.66
2002	84.806
2003	83.931
2004	83.036
2005	82.122
2006	81.229
2007	81.7
2008	82.149
2009	82.565
2010	82.945
2011	83.31
2012	83.645
2013	83.945
2014	84.206
2015	84.093
2016	83.993
2017	83.961
2018	83.909
2019	83.837
2020	83.743
2021	83.644
2022	83.527
2023	83.397
2024	83.263
2025	83.132
2026	83.016
2027	82.905
2028	82.792
2029	82.672
2030	82.538