Year	Percent
1990	95.571
1991	95.361
1992	95.089
1993	95.045
1994	95.197
1995	95.088
1996	95.292
1997	94.999
1998	94.714
1999	94.354
2000	94.328
2001	94.011
2002	93.892
2003	94.123
2004	94.11
2005	93.965
2006	94.114
2007	94.163
2008	94.452
2009	94.338
2010	94.211
2011	93.711
2012	93.551
2013	93.338
2014	92.902
2015	92.44
2016	92.42
2017	92.393
2018	92.366
2019	92.341
2020	92.315
2021	92.291
2022	92.267
2023	92.244
2024	92.222
2025	92.201
2026	92.181
2027	92.16
2028	92.139
2029	92.116
2030	92.092