Year	Percent
1990	88.241
1991	88.12
1992	88.008
1993	87.909
1994	87.826
1995	87.761
1996	87.595
1997	87.452
1998	87.321
1999	87.186
2000	87.035
2001	86.873
2002	86.708
2003	86.537
2004	86.357
2005	86.171
2006	85.951
2007	85.383
2008	84.804
2009	84.21
2010	83.597
2011	82.988
2012	82.37
2013	81.742
2014	81.104
2015	80.458
2016	79.805
2017	79.807
2018	79.806
2019	79.802
2020	79.794
2021	79.782
2022	79.774
2023	79.76
2024	79.733
2025	79.685
2026	79.619
2027	79.538
2028	79.442
2029	79.331
2030	79.206