Year	Percent
1990	76.279
1991	76.553
1992	76.895
1993	77.295
1994	77.481
1995	77.658
1996	77.81
1997	77.832
1998	77.685
1999	77.541
2000	77.241
2001	77.015
2002	76.88
2003	76.887
2004	76.925
2005	76.971
2006	77.025
2007	76.996
2008	76.964
2009	76.978
2010	76.891
2011	76.641
2012	76.433
2013	76.253
2014	76.067
2015	75.848
2016	75.701
2017	75.582
2018	75.481
2019	75.38
2020	75.279
2021	75.218
2022	75.156
2023	75.092
2024	75.027
2025	74.956
2026	74.93
2027	74.907
2028	74.888
2029	74.88
2030	74.894