Year	Percent
1990	93.815
1991	94.194
1992	93.882
1993	93.412
1994	93.462
1995	93.114
1996	92.902
1997	93.317
1998	93.337
1999	93.618
2000	93.676
2001	93.501
2002	93.263
2003	93.259
2004	92.914
2005	93.603
2006	93.8
2007	93.788
2008	93.475
2009	93.2
2010	93.181
2011	93.164
2012	93.081
2013	92.837
2014	92.57
2015	92.451
2016	91.985
2017	92.005
2018	92.032
2019	92.064
2020	92.099
2021	92.138
2022	92.179
2023	92.22
2024	92.262
2025	92.305
2026	92.348
2027	92.391
2028	92.432
2029	92.471
2030	92.507