Year	Percent
1990	84.525
1991	84.333
1992	84.044
1993	83.69
1994	83.302
1995	82.796
1996	82.594
1997	82.476
1998	82.314
1999	81.605
2000	80.892
2001	80.167
2002	79.413
2003	78.623
2004	77.793
2005	76.925
2006	76.051
2007	75.15
2008	74.219
2009	73.258
2010	72.273
2011	71.272
2012	70.261
2013	69.248
2014	68.246
2015	67.263
2016	66.284
2017	66.159
2018	66.056
2019	65.968
2020	65.894
2021	65.823
2022	65.766
2023	65.712
2024	65.652
2025	65.585
2026	65.501
2027	65.409
2028	65.311
2029	65.21
2030	65.11