Year	Percent
1990	86.615
1991	86.751
1992	86.423
1993	86.244
1994	86.291
1995	86.165
1996	85.958
1997	85.693
1998	85.462
1999	85.243
2000	85.081
2001	85.129
2002	84.989
2003	85.141
2004	85.202
2005	84.877
2006	84.509
2007	84.221
2008	82.987
2009	81.709
2010	82.418
2011	83.215
2012	83.028
2013	83.124
2014	83.265
2015	83.35
2016	83.226
2017	83.193
2018	83.14
2019	83.082
2020	83.028
2021	83.003
2022	82.982
2023	82.962
2024	82.939
2025	82.914
2026	82.91
2027	82.907
2028	82.904
2029	82.9
2030	82.898