Year	Percent
1990	85.798
1991	86.185
1992	86.331
1993	86.416
1994	86.424
1995	86.305
1996	87.108
1997	87.283
1998	87.441
1999	87.25
2000	87.456
2001	86.582
2002	85.682
2003	84.758
2004	83.811
2005	82.843
2006	81.895
2007	82.539
2008	83.168
2009	83.768
2010	84.33
2011	84.876
2012	85.386
2013	85.864
2014	86.315
2015	86.239
2016	86.193
2017	86.243
2018	86.286
2019	86.316
2020	86.33
2021	86.34
2022	86.337
2023	86.323
2024	86.305
2025	86.287
2026	86.274
2027	86.264
2028	86.251
2029	86.232
2030	86.204