Year	Percent
1990	53.684
1991	53.564
1992	53.23
1993	52.933
1994	52.741
1995	52.644
1996	52.721
1997	53.332
1998	53.516
1999	53.675
2000	53.954
2001	53.958
2002	54.01
2003	53.752
2004	53.845
2005	53.949
2006	54.077
2007	54.229
2008	54.36
2009	54.47
2010	54.589
2011	54.702
2012	54.805
2013	54.913
2014	54.956
2015	54.997
2016	55.017
2017	54.996
2018	54.977
2019	54.972
2020	54.986
2021	55.018
2022	55.069
2023	55.138
2024	55.221
2025	55.318
2026	55.424
2027	55.544
2028	55.672
2029	55.803
2030	55.933