Year	Percent
1990	44.812
1991	46.558
1992	46.84
1993	48.465
1994	48.209
1995	48.002
1996	49.078
1997	49.891
1998	50.298
1999	52.765
2000	50.348
2001	52.048
2002	53.745
2003	54.654
2004	54.435
2005	56.011
2006	57.639
2007	57.518
2008	56.756
2009	56.242
2010	55.721
2011	55.221
2012	54.718
2013	54.209
2014	53.695
2015	53.181
2016	53.402
2017	53.504
2018	53.605
2019	53.708
2020	53.818
2021	53.938
2022	54.068
2023	54.203
2024	54.337
2025	54.468
2026	54.595
2027	54.72
2028	54.842
2029	54.964
2030	55.086