Year	Percent
1990	84.103
1991	83.474
1992	82.909
1993	81.396
1994	81.711
1995	80.722
1996	80.175
1997	79.614
1998	79.386
1999	78.398
2000	76.096
2001	75.297
2002	74.154
2003	72.905
2004	74.222
2005	74.629
2006	72.97
2007	73.143
2008	73.696
2009	73.91
2010	74.501
2011	75.409
2012	74.731
2013	75.369
2014	76.464
2015	76.977
2016	77.551
2017	77.426
2018	77.297
2019	77.16
2020	77.013
2021	76.886
2022	76.762
2023	76.637
2024	76.504
2025	76.36
2026	76.21
2027	76.048
2028	75.877
2029	75.703
2030	75.525