Year	Percent
1990	77.223
1991	77.096
1992	77.162
1993	77.139
1994	76.995
1995	76.717
1996	76.262
1997	75.981
1998	77.8
1999	77.744
2000	77.454
2001	77.28
2002	77.259
2003	77.137
2004	76.882
2005	76.54
2006	76.372
2007	76.145
2008	75.918
2009	75.696
2010	75.426
2011	74.991
2012	75.154
2013	75.156
2014	75.054
2015	74.816
2016	74.61
2017	74.463
2018	74.316
2019	74.169
2020	74.023
2021	73.876
2022	73.729
2023	73.582
2024	73.435
2025	73.288
2026	73.141
2027	72.994
2028	72.848
2029	72.701
2030	72.554