Year	Percent
1990	86.608
1991	86.529
1992	86.47
1993	86.425
1994	86.387
1995	86.168
1996	85.934
1997	85.688
1998	85.437
1999	85.195
2000	84.969
2001	85.091
2002	85.224
2003	85.366
2004	85.512
2005	85.659
2006	85.169
2007	84.681
2008	84.195
2009	83.707
2010	83.215
2011	82.708
2012	82.192
2013	82.095
2014	81.979
2015	81.842
2016	81.657
2017	81.708
2018	81.765
2019	81.825
2020	81.89
2021	81.957
2022	82.028
2023	82.107
2024	82.206
2025	82.329
2026	82.472
2027	82.639
2028	82.816
2029	82.98
2030	83.117