Year	Percent
1990	94.606
1991	94.489
1992	94.366
1993	94.239
1994	94.109
1995	93.976
1996	93.829
1997	93.705
1998	93.576
1999	93.442
2000	93.299
2001	93.146
2002	92.988
2003	92.826
2004	92.662
2005	92.495
2006	92.356
2007	92.209
2008	92.051
2009	91.883
2010	91.864
2011	91.65
2012	91.318
2013	91.19
2014	91.085
2015	90.913
2016	90.781
2017	90.688
2018	90.591
2019	90.497
2020	90.408
2021	90.32
2022	90.239
2023	90.164
2024	90.097
2025	90.037
2026	89.983
2027	89.936
2028	89.895
2029	89.862
2030	89.833