Year	Percent
1990	56.311
1991	57.236
1992	58.043
1993	58.85
1994	59.788
1995	60.903
1996	61.729
1997	62.733
1998	63.705
1999	63.11
2000	62.445
2001	63.87
2002	65.261
2003	66.62
2004	67.95
2005	69.257
2006	70.539
2007	71.125
2008	71.688
2009	72.231
2010	67.856
2011	72.27
2012	76.29
2013	79.884
2014	80.181
2015	80.419
2016	80.652
2017	80.909
2018	81.159
2019	81.4
2020	81.633
2021	81.859
2022	82.077
2023	82.287
2024	82.49
2025	82.687
2026	82.879
2027	83.067
2028	83.254
2029	83.443
2030	83.637