Year	Percent
1990	88.462
1991	88.442
1992	88.409
1993	88.361
1994	88.301
1995	88.234
1996	88.219
1997	88.22
1998	88.233
1999	88.253
2000	88.276
2001	88.364
2002	88.47
2003	88.585
2004	88.7
2005	88.807
2006	88.737
2007	88.657
2008	88.566
2009	88.462
2010	88.351
2011	88.334
2012	88.338
2013	88.368
2014	88.429
2015	88.519
2016	88.548
2017	88.558
2018	88.575
2019	88.598
2020	88.625
2021	88.672
2022	88.723
2023	88.781
2024	88.854
2025	88.946
2026	89.069
2027	89.208
2028	89.35
2029	89.479
2030	89.584