Year	Percent
1990	68.257
1991	68.263
1992	68.162
1993	68.119
1994	68.122
1995	68.074
1996	68.045
1997	67.962
1998	66.177
1999	64.327
2000	67.1
2001	69.886
2002	72.601
2003	75.2
2004	77.646
2005	77.682
2006	77.776
2007	77.873
2008	77.973
2009	78.077
2010	78.184
2011	78.356
2012	78.557
2013	78.717
2014	78.861
2015	78.968
2016	79.071
2017	79.431
2018	79.777
2019	80.104
2020	80.41
2021	80.699
2022	80.971
2023	81.23
2024	81.479
2025	81.722
2026	81.965
2027	82.203
2028	82.445
2029	82.7
2030	82.976