Year	Percent
1990	84.653
1991	84.425
1992	84.205
1993	83.962
1994	83.721
1995	83.154
1996	82.783
1997	82.567
1998	82.331
1999	81.324
2000	81.392
2001	82.094
2002	81.768
2003	81.461
2004	81.74
2005	81.473
2006	81.325
2007	81.479
2008	81.415
2009	81.415
2010	80.796
2011	80.982
2012	80.883
2013	80.029
2014	79.324
2015	77.761
2016	77.467
2017	77.256
2018	77.047
2019	76.819
2020	76.561
2021	76.274
2022	75.963
2023	75.632
2024	75.286
2025	74.931
2026	74.567
2027	74.196
2028	73.821
2029	73.447
2030	73.079