Year	Percent
1990	96.314
1991	96.336
1992	96.332
1993	96.328
1994	96.312
1995	96.293
1996	96.271
1997	96.249
1998	96.221
1999	96.153
2000	96.048
2001	95.945
2002	95.818
2003	95.656
2004	95.481
2005	95.292
2006	95.1
2007	94.913
2008	94.745
2009	94.563
2010	94.387
2011	94.286
2012	94.144
2013	93.971
2014	93.796
2015	93.627
2016	93.478
2017	93.407
2018	93.334
2019	93.26
2020	93.187
2021	93.116
2022	93.046
2023	92.976
2024	92.907
2025	92.837
2026	92.771
2027	92.704
2028	92.638
2029	92.574
2030	92.511