Year	Percent
1990	84.93
1991	85.291
1992	85.55
1993	85.787
1994	85.713
1995	85.669
1996	85.62
1997	85.491
1998	85.245
1999	85.176
2000	84.966
2001	84.809
2002	84.582
2003	84.426
2004	84.199
2005	83.934
2006	83.669
2007	83.331
2008	83.113
2009	83.102
2010	82.933
2011	82.741
2012	82.603
2013	82.511
2014	82.416
2015	82.305
2016	82.271
2017	82.26
2018	82.26
2019	82.266
2020	82.272
2021	82.28
2022	82.29
2023	82.301
2024	82.313
2025	82.33
2026	82.352
2027	82.375
2028	82.398
2029	82.418
2030	82.434