Year	Percent
1990	94.674
1991	94.612
1992	94.547
1993	94.479
1994	94.412
1995	94.361
1996	94.337
1997	94.326
1998	94.326
1999	94.331
2000	94.34
2001	94.376
2002	94.406
2003	94.42
2004	94.41
2005	94.373
2006	94.303
2007	94.214
2008	94.118
2009	94.034
2010	93.261
2011	92.217
2012	87.399
2013	93.395
2014	92.815
2015	95.164
2016	95.115
2017	94.912
2018	94.706
2019	94.502
2020	94.303
2021	94.11
2022	93.924
2023	93.743
2024	93.561
2025	93.374
2026	93.179
2027	92.978
2028	92.767
2029	92.544
2030	92.31