Year	Percent
1990	68.638
1991	68.797
1992	69.089
1993	69.32
1994	69.568
1995	69.774
1996	69.947
1997	70.09
1998	70.216
1999	70.309
2000	70.377
2001	70.409
2002	70.415
2003	70.4
2004	70.347
2005	70.287
2006	70.209
2007	70.105
2008	69.999
2009	69.893
2010	69.793
2011	69.693
2012	69.593
2013	69.506
2014	69.437
2015	69.389
2016	69.357
2017	69.347
2018	69.359
2019	69.388
2020	69.434
2021	69.493
2022	69.565
2023	69.647
2024	69.737
2025	69.83
2026	69.924
2027	70.022
2028	70.11
2029	70.175
2030	70.205