Year	Percent
1990	52.965
1991	53.068
1992	53.268
1993	53.541
1994	53.861
1995	54.28
1996	54.378
1997	54.438
1998	54.543
1999	54.921
2000	55.294
2001	55.674
2002	56.051
2003	56.428
2004	56.806
2005	57.186
2006	57.565
2007	57.947
2008	58.331
2009	58.716
2010	59.1
2011	59.475
2012	59.851
2013	60.226
2014	60.6
2015	60.969
2016	61.333
2017	61.54
2018	61.746
2019	61.951
2020	62.156
2021	62.357
2022	62.558
2023	62.763
2024	62.974
2025	63.193
2026	63.417
2027	63.648
2028	63.884
2029	64.124
2030	64.366