Year	Percent
1990	80.962
1991	81.067
1992	81.642
1993	80.033
1994	78.033
1995	77.455
1996	76.039
1997	73.925
1998	72.537
1999	75.797
2000	75.853
2001	74.53
2002	74.87
2003	74.64
2004	75.137
2005	75.412
2006	75.57
2007	76.712
2008	77.714
2009	77.441
2010	77.732
2011	78.082
2012	78.298
2013	78.617
2014	78.995
2015	79.456
2016	80.012
2017	80.024
2018	79.938
2019	79.795
2020	79.626
2021	79.424
2022	79.186
2023	78.93
2024	78.674
2025	78.433
2026	78.205
2027	77.999
2028	77.804
2029	77.607
2030	77.41