Year	Percent
1990	94.586
1991	94.608
1992	94.607
1993	94.664
1994	94.671
1995	94.217
1996	93.662
1997	93.041
1998	92.353
1999	91.596
2000	91.363
2001	91.125
2002	90.88
2003	90.629
2004	90.373
2005	90.115
2006	89.855
2007	89.589
2008	89.318
2009	89.042
2010	88.764
2011	88.459
2012	88.134
2013	87.782
2014	87.391
2015	87.523
2016	87.603
2017	87.563
2018	87.521
2019	87.478
2020	87.437
2021	87.396
2022	87.357
2023	87.314
2024	87.262
2025	87.2
2026	87.129
2027	87.049
2028	86.961
2029	86.867
2030	86.769