Year	Percent
1990	79.844
1991	79.938
1992	79.979
1993	80.283
1994	80.228
1995	80.262
1996	80.449
1997	80.529
1998	80.546
1999	80.62
2000	80.677
2001	80.722
2002	80.735
2003	80.619
2004	80.237
2005	79.936
2006	79.97
2007	79.877
2008	79.709
2009	79.471
2010	79.078
2011	78.97
2012	78.689
2013	78.403
2014	78.058
2015	77.743
2016	77.66
2017	77.579
2018	77.505
2019	77.441
2020	77.39
2021	77.351
2022	77.32
2023	77.296
2024	77.28
2025	77.27
2026	77.268
2027	77.27
2028	77.276
2029	77.285
2030	77.299