Year	Percent
1990	69.716
1991	69.713
1992	69.717
1993	69.737
1994	69.678
1995	69.693
1996	69.691
1997	69.659
1998	69.631
1999	69.648
2000	69.605
2001	69.671
2002	69.747
2003	69.732
2004	69.719
2005	69.693
2006	69.631
2007	69.6
2008	69.552
2009	69.54
2010	69.55
2011	69.565
2012	69.572
2013	69.576
2014	69.575
2015	69.612
2016	69.59
2017	69.578
2018	69.566
2019	69.554
2020	69.542
2021	69.53
2022	69.519
2023	69.507
2024	69.495
2025	69.483
2026	69.471
2027	69.459
2028	69.447
2029	69.435
2030	69.423