Year	Percent
1990	78.718
1991	79.019
1992	79.103
1993	79.085
1994	79.239
1995	79.314
1996	79.144
1997	78.999
1998	79.071
1999	78.435
2000	78.126
2001	77.761
2002	77.084
2003	76.435
2004	75.943
2005	76.34
2006	76.876
2007	77.419
2008	76.994
2009	77.457
2010	77.201
2011	76.886
2012	77.101
2013	76.798
2014	77.049
2015	77.308
2016	77.002
2017	76.749
2018	76.495
2019	76.228
2020	75.94
2021	75.646
2022	75.34
2023	75.021
2024	74.688
2025	74.341
2026	74.014
2027	73.678
2028	73.338
2029	73.006
2030	72.687