Year	Percent
1990	50.525
1991	50.416
1992	50.291
1993	50.125
1994	49.922
1995	49.811
1996	49.741
1997	49.637
1998	49.579
1999	49.47
2000	49.45
2001	49.472
2002	49.485
2003	49.463
2004	49.471
2005	49.53
2006	49.563
2007	49.538
2008	49.578
2009	49.624
2010	49.664
2011	49.799
2012	49.904
2013	49.977
2014	50.054
2015	50.074
2016	50.006
2017	50.046
2018	50.086
2019	50.125
2020	50.165
2021	50.205
2022	50.245
2023	50.284
2024	50.324
2025	50.364
2026	50.404
2027	50.444
2028	50.483
2029	50.523
2030	50.563