Year	Percent
1990	69.948
1991	69.951
1992	69.931
1993	69.895
1994	69.849
1995	69.797
1996	69.75
1997	69.713
1998	69.669
1999	69.6
2000	69.507
2001	69.42
2002	69.323
2003	69.253
2004	69.158
2005	69.453
2006	69.797
2007	70.221
2008	70.669
2009	70.991
2010	71.357
2011	71.734
2012	72.067
2013	72.354
2014	72.604
2015	72.829
2016	73.045
2017	73.27
2018	73.46
2019	73.572
2020	73.585
2021	73.518
2022	73.373
2023	73.171
2024	72.945
2025	72.717
2026	72.503
2027	72.294
2028	72.1
2029	71.932
2030	71.796