Year	Percent
1990	76.022
1991	75.058
1992	75.07
1993	74.697
1994	74.489
1995	74.31
1996	74.928
1997	74.829
1998	74.757
1999	75.119
2000	75.062
2001	74.843
2002	75.228
2003	75.375
2004	75.457
2005	75.201
2006	74.969
2007	74.774
2008	74.802
2009	74.997
2010	74.987
2011	74.761
2012	75.341
2013	75.551
2014	75.406
2015	75.51
2016	75.551
2017	75.528
2018	75.496
2019	75.462
2020	75.428
2021	75.378
2022	75.328
2023	75.288
2024	75.273
2025	75.291
2026	75.324
2027	75.391
2028	75.483
2029	75.584
2030	75.685