Year	Percent
1990	51.801
1991	52.082
1992	52.25
1993	52.646
1994	53.087
1995	53.252
1996	53.413
1997	53.574
1998	53.736
1999	53.899
2000	54.066
2001	54.243
2002	54.424
2003	54.608
2004	54.795
2005	54.987
2006	55.179
2007	55.385
2008	55.2
2009	56.27
2010	53.865
2011	55.425
2012	60.292
2013	58.735
2014	55.977
2015	55.929
2016	56.274
2017	56.579
2018	56.891
2019	57.196
2020	57.487
2021	57.778
2022	58.054
2023	58.318
2024	58.579
2025	58.84
2026	59.118
2027	59.397
2028	59.673
2029	59.942
2030	60.201