Year	Percent
1990	81.123
1991	81.156
1992	81.317
1993	81.984
1994	82.907
1995	83.847
1996	83.052
1997	82.326
1998	81.83
1999	81.647
2000	81.733
2001	81.306
2002	81.336
2003	81.727
2004	81.913
2005	82.316
2006	81.958
2007	81.958
2008	82.404
2009	83.615
2010	84.619
2011	84.801
2012	84.958
2013	85.265
2014	85.49
2015	85.522
2016	84.667
2017	84.065
2018	83.685
2019	83.457
2020	83.302
2021	82.601
2022	81.988
2023	81.502
2024	81.161
2025	80.937
2026	80.404
2027	79.952
2028	79.598
2029	79.343
2030	79.162