Year	Percent
1990	78.865
1991	79.002
1992	78.649
1993	80.468
1994	80.649
1995	80.269
1996	79.049
1997	78.391
1998	77.623
1999	77.102
2000	77.186
2001	76.729
2002	75.413
2003	75.08
2004	75.678
2005	75.838
2006	76.35
2007	77.091
2008	76.997
2009	75.963
2010	76.352
2011	76.092
2012	76.166
2013	76.268
2014	76.283
2015	76.455
2016	75.961
2017	75.964
2018	75.972
2019	75.973
2020	75.959
2021	75.921
2022	75.877
2023	75.825
2024	75.763
2025	75.69
2026	75.594
2027	75.487
2028	75.39
2029	75.331
2030	75.327