Year	Percent
1990	56.206
1991	56.043
1992	56.476
1993	56.594
1994	57.556
1995	57.756
1996	58.084
1997	58.614
1998	58.752
1999	58.921
2000	59.023
2001	58.807
2002	58.591
2003	58.458
2004	58.154
2005	58.242
2006	58.341
2007	58.259
2008	58.458
2009	58.145
2010	57.5
2011	56.929
2012	56.7
2013	56.292
2014	56.11
2015	55.832
2016	55.99
2017	55.735
2018	55.478
2019	55.219
2020	54.957
2021	54.692
2022	54.428
2023	54.172
2024	53.933
2025	53.716
2026	53.528
2027	53.366
2028	53.223
2029	53.087
2030	52.953