Year	Percent
1990	53.982
1991	54.203
1992	54.514
1993	54.759
1994	54.997
1995	55.182
1996	55.351
1997	55.483
1998	55.602
1999	55.708
2000	55.812
2001	55.919
2002	56.022
2003	56.114
2004	56.175
2005	56.226
2006	56.266
2007	56.286
2008	56.312
2009	56.353
2010	56.415
2011	56.495
2012	56.583
2013	56.688
2014	56.807
2015	56.937
2016	57.085
2017	57.247
2018	57.402
2019	57.521
2020	57.588
2021	57.619
2022	57.597
2023	57.542
2024	57.485
2025	57.447
2026	57.434
2027	57.435
2028	57.438
2029	57.43
2030	57.402