Year	Percent
1990	57.349
1991	57.362
1992	57.366
1993	58.222
1994	59.073
1995	59.918
1996	60.741
1997	61.555
1998	62.357
1999	63.149
2000	63.929
2001	64.69
2002	65.441
2003	66.139
2004	66.769
2005	67.332
2006	67.817
2007	68.241
2008	68.609
2009	68.934
2010	69.224
2011	68.088
2012	68.154
2013	68.248
2014	68.344
2015	68.413
2016	68.497
2017	68.693
2018	68.895
2019	69.098
2020	69.299
2021	69.494
2022	69.69
2023	69.886
2024	70.087
2025	70.292
2026	70.495
2027	70.704
2028	70.919
2029	71.143
2030	71.376