Year	Percent
1990	73.923
1991	73.873
1992	74.011
1993	74.184
1994	74.359
1995	74.433
1996	74.356
1997	74.133
1998	73.915
1999	73.81
2000	74.071
2001	74.464
2002	74.949
2003	75.473
2004	75.965
2005	76.394
2006	76.737
2007	77.063
2008	77.397
2009	77.759
2010	78.154
2011	78.611
2012	79.095
2013	79.574
2014	79.996
2015	80.322
2016	80.555
2017	80.537
2018	80.437
2019	80.297
2020	80.145
2021	79.974
2022	79.777
2023	79.565
2024	79.357
2025	79.169
2026	79.007
2027	78.875
2028	78.772
2029	78.688
2030	78.625