Year	Percent
1990	86.619
1991	86.693
1992	86.672
1993	86.59
1994	86.544
1995	86.647
1996	86.712
1997	86.764
1998	86.828
1999	86.869
2000	86.85
2001	86.892
2002	86.85
2003	86.745
2004	86.618
2005	86.502
2006	86.435
2007	86.358
2008	86.26
2009	86.116
2010	85.91
2011	85.786
2012	85.61
2013	85.393
2014	85.157
2015	84.913
2016	84.744
2017	84.673
2018	84.604
2019	84.538
2020	84.475
2021	84.415
2022	84.358
2023	84.304
2024	84.256
2025	84.213
2026	84.174
2027	84.14
2028	84.109
2029	84.079
2030	84.047