Year	Percent
1990	78.208
1991	78.329
1992	78.06
1993	77.808
1994	77.527
1995	77.195
1996	76.83
1997	76.437
1998	76.028
1999	75.639
2000	75.287
2001	75.018
2002	75.244
2003	75.315
2004	75.27
2005	75.572
2006	75.568
2007	75.741
2008	75.604
2009	75.487
2010	75.345
2011	75.398
2012	75.551
2013	75.675
2014	75.781
2015	75.814
2016	75.895
2017	75.93
2018	75.941
2019	75.914
2020	75.852
2021	75.785
2022	75.687
2023	75.541
2024	75.336
2025	75.067
2026	74.788
2027	74.456
2028	74.073
2029	73.668
2030	73.258