Year	Percent
1990	52.32
1991	52.021
1992	51.97
1993	51.752
1994	52.674
1995	53.664
1996	53.852
1997	53.671
1998	53.743
1999	53.749
2000	54.623
2001	55.195
2002	55.402
2003	56.053
2004	55.803
2005	57.05
2006	57.612
2007	58.2
2008	58.665
2009	58.82
2010	58.707
2011	58.953
2012	58.824
2013	58.704
2014	58.645
2015	59.058
2016	59.24
2017	59.21
2018	59.178
2019	59.139
2020	59.09
2021	59.037
2022	58.98
2023	58.921
2024	58.862
2025	58.807
2026	58.784
2027	58.769
2028	58.762
2029	58.76
2030	58.76