Year	Percent
1990	46.267
1991	46.725
1992	47.995
1993	49.021
1994	50.505
1995	51.288
1996	51.119
1997	51.013
1998	51.111
1999	52.298
2000	53.241
2001	53.483
2002	53.087
2003	54.01
2004	54.494
2005	55.046
2006	55.431
2007	55.899
2008	55.952
2009	56.832
2010	57.029
2011	56.795
2012	57.967
2013	58.132
2014	59.028
2015	58.986
2016	59.372
2017	59.341
2018	59.32
2019	59.306
2020	59.299
2021	59.314
2022	59.346
2023	59.389
2024	59.428
2025	59.458
2026	59.5
2027	59.537
2028	59.578
2029	59.634
2030	59.712