Year	Percent
1990	84.509
1991	83.965
1992	84.054
1993	83.8
1994	83.291
1995	83.305
1996	83.279
1997	83.287
1998	83.331
1999	83.125
2000	82.939
2001	82.335
2002	81.75
2003	80.873
2004	80.545
2005	80.379
2006	80.521
2007	80.241
2008	79.927
2009	78.794
2010	77.959
2011	77.368
2012	77.461
2013	77.313
2014	77.152
2015	77.214
2016	77.548
2017	77.45
2018	77.355
2019	77.266
2020	77.186
2021	77.085
2022	76.982
2023	76.889
2024	76.82
2025	76.785
2026	76.752
2027	76.749
2028	76.762
2029	76.768
2030	76.748