Year	Percent
1990	58.911
1991	58.792
1992	58.954
1993	58.849
1994	58.721
1995	58.517
1996	58.359
1997	58.115
1998	57.925
1999	58.143
2000	58.098
2001	57.848
2002	57.687
2003	57.482
2004	57.393
2005	57.28
2006	57.344
2007	57.244
2008	57.572
2009	57.892
2010	58.068
2011	58.07
2012	58.174
2013	58.318
2014	58.547
2015	58.804
2016	59.235
2017	59.396
2018	59.51
2019	59.565
2020	59.554
2021	59.467
2022	59.325
2023	59.127
2024	58.876
2025	58.575
2026	58.221
2027	57.829
2028	57.421
2029	57.021
2030	56.648