Year	Percent
1990	49.699
1991	49.927
1992	50.093
1993	50.256
1994	50.478
1995	50.787
1996	50.989
1997	51.258
1998	51.511
1999	51.221
2000	50.963
2001	52.014
2002	53.105
2003	54.222
2004	55.333
2005	56.421
2006	57.528
2007	57.857
2008	58.177
2009	58.496
2010	55.654
2011	59.692
2012	63.509
2013	67.076
2014	67.379
2015	67.654
2016	67.951
2017	68.411
2018	68.859
2019	69.283
2020	69.676
2021	70.033
2022	70.367
2023	70.673
2024	70.951
2025	71.2
2026	71.414
2027	71.603
2028	71.784
2029	71.983
2030	72.214