Year	Percent
1990	67.761
1991	67.762
1992	67.654
1993	67.605
1994	67.603
1995	67.548
1996	67.516
1997	67.431
1998	65.802
1999	64.111
2000	66.812
2001	69.523
2002	72.166
2003	74.7
2004	77.089
2005	77.085
2006	77.132
2007	77.182
2008	77.235
2009	77.295
2010	77.36
2011	77.491
2012	77.697
2013	77.863
2014	78.01
2015	78.114
2016	78.209
2017	78.542
2018	78.859
2019	79.159
2020	79.441
2021	79.705
2022	79.955
2023	80.193
2024	80.424
2025	80.65
2026	80.874
2027	81.094
2028	81.318
2029	81.555
2030	81.811