Year	Percent
1990	97.283
1991	97.232
1992	97.02
1993	96.853
1994	97.237
1995	96.791
1996	96.692
1997	96.675
1998	96.761
1999	96.84
2000	96.846
2001	96.751
2002	96.56
2003	96.445
2004	96.274
2005	96.134
2006	95.994
2007	95.906
2008	95.798
2009	95.746
2010	95.662
2011	95.572
2012	95.447
2013	95.368
2014	95.27
2015	95.195
2016	95.143
2017	95.182
2018	95.229
2019	95.263
2020	95.269
2021	95.25
2022	95.205
2023	95.144
2024	95.083
2025	95.029
2026	94.98
2027	94.937
2028	94.896
2029	94.851
2030	94.799