Year	Percent
1990	93.395
1991	93.048
1992	92.987
1993	92.585
1994	91.776
1995	91.62
1996	91.786
1997	91.866
1998	91.85
1999	91.782
2000	91.685
2001	91.34
2002	91.063
2003	90.579
2004	90.466
2005	90.496
2006	90.599
2007	90.86
2008	90.539
2009	89.749
2010	89.262
2011	88.692
2012	88.678
2013	88.404
2014	88.184
2015	88.273
2016	88.53
2017	88.46
2018	88.393
2019	88.33
2020	88.267
2021	88.207
2022	88.148
2023	88.088
2024	88.026
2025	87.96
2026	87.889
2027	87.813
2028	87.733
2029	87.648
2030	87.559