Year	Percent
1990	78.621
1991	78.716
1992	78.818
1993	78.923
1994	79.007
1995	79.084
1996	79.145
1997	79.181
1998	79.186
1999	79.164
2000	79.09
2001	78.994
2002	78.85
2003	78.678
2004	78.486
2005	78.287
2006	78.065
2007	77.852
2008	77.654
2009	77.468
2010	77.267
2011	77.081
2012	76.895
2013	76.733
2014	76.627
2015	76.585
2016	76.588
2017	76.642
2018	76.723
2019	76.808
2020	76.884
2021	76.957
2022	77.022
2023	77.084
2024	77.15
2025	77.226
2026	77.313
2027	77.406
2028	77.499
2029	77.584
2030	77.66
