Year	Percent
1990	97.558
1991	97.562
1992	97.559
1993	97.552
1994	97.526
1995	97.503
1996	97.445
1997	97.382
1998	97.313
1999	97.237
2000	97.155
2001	97.074
2002	96.988
2003	96.899
2004	96.806
2005	96.711
2006	96.613
2007	96.512
2008	96.408
2009	96.3
2010	96.186
2011	96.093
2012	95.995
2013	95.889
2014	95.795
2015	95.704
2016	95.607
2017	95.564
2018	95.522
2019	95.483
2020	95.446
2021	95.411
2022	95.379
2023	95.348
2024	95.317
2025	95.286
2026	95.253
2027	95.22
2028	95.186
2029	95.148
2030	95.108