Year	Percent
1990	71.047
1991	70.987
1992	70.947
1993	70.926
1994	70.916
1995	70.904
1996	70.877
1997	70.858
1998	70.837
1999	70.813
2000	70.788
2001	70.74
2002	70.701
2003	70.669
2004	70.646
2005	70.63
2006	70.616
2007	70.611
2008	70.611
2009	70.613
2010	70.615
2011	70.615
2012	70.617
2013	70.623
2014	70.641
2015	70.673
2016	70.717
2017	70.797
2018	70.886
2019	70.972
2020	71.051
2021	71.12
2022	71.183
2023	71.245
2024	71.308
2025	71.376
2026	71.44
2027	71.508
2028	71.578
2029	71.646
2030	71.711