Year	Percent
1990	86.245
1991	86.313
1992	86.14
1993	86.056
1994	85.942
1995	85.849
1996	85.754
1997	85.685
1998	85.621
1999	85.437
2000	85.192
2001	84.995
2002	84.788
2003	84.525
2004	84.25
2005	83.945
2006	83.637
2007	83.329
2008	83.035
2009	82.679
2010	82.306
2011	82.052
2012	81.718
2013	81.326
2014	80.926
2015	80.53
2016	80.151
2017	79.854
2018	79.56
2019	79.291
2020	79.057
2021	78.839
2022	78.657
2023	78.499
2024	78.348
2025	78.193
2026	78.024
2027	77.857
2028	77.686
2029	77.502
2030	77.3