Year	Percent
1990	86.266
1991	86.282
1992	86.204
1993	86.139
1994	86.037
1995	85.901
1996	85.776
1997	85.679
1998	85.652
1999	85.643
2000	85.546
2001	85.482
2002	85.401
2003	85.288
2004	85.143
2005	84.988
2006	84.858
2007	84.707
2008	84.615
2009	84.575
2010	84.926
2011	85.335
2012	85.806
2013	86.306
2014	86.94
2015	87.158
2016	86.949
2017	87.092
2018	87.178
2019	87.213
2020	87.205
2021	87.156
2022	87.057
2023	86.92
2024	86.768
2025	86.616
2026	86.472
2027	86.329
2028	86.196
2029	86.082
2030	85.996