Year	Percent
1990	97.001
1991	96.999
1992	96.998
1993	96.997
1994	96.996
1995	96.95
1996	96.903
1997	96.853
1998	96.8
1999	96.744
2000	96.684
2001	96.802
2002	96.914
2003	97.019
2004	97.122
2005	97.223
2006	97.291
2007	97.352
2008	97.407
2009	97.454
2010	97.495
2011	97.34
2012	97.161
2013	97.144
2014	97.123
2015	97.098
2016	97.065
2017	97.101
2018	97.136
2019	97.172
2020	97.207
2021	97.242
2022	97.277
2023	97.311
2024	97.346
2025	97.381
2026	97.416
2027	97.452
2028	97.488
2029	97.524
2030	97.56