Year	Percent
1990	59.303
1991	59.646
1992	59.947
1993	60.44
1994	60.967
1995	61.547
1996	62.123
1997	62.695
1998	63.263
1999	63.828
2000	64.39
2001	64.949
2002	65.502
2003	66.047
2004	66.586
2005	67.119
2006	67.65
2007	68.177
2008	65.466
2009	65.6
2010	65.042
2011	66.274
2012	73.373
2013	72.146
2014	68.967
2015	69.844
2016	68.668
2017	69.084
2018	69.499
2019	69.914
2020	70.327
2021	70.739
2022	71.15
2023	71.56
2024	71.969
2025	72.377
2026	72.785
2027	73.194
2028	73.602
2029	74.009
2030	74.413