Year	Percent
1990	90.002
1991	90.067
1992	90.142
1993	90.223
1994	90.305
1995	90.385
1996	90.392
1997	90.39
1998	90.379
1999	90.359
2000	90.328
2001	90.372
2002	90.406
2003	90.433
2004	90.453
2005	90.468
2006	90.486
2007	90.776
2008	91.058
2009	91.337
2010	91.616
2011	91.889
2012	92.157
2013	92.423
2014	92.686
2015	92.547
2016	92.407
2017	92.518
2018	92.632
2019	92.746
2020	92.859
2021	92.974
2022	93.087
2023	93.198
2024	93.306
2025	93.409
2026	93.509
2027	93.605
2028	93.694
2029	93.773
2030	93.838
