Year	Percent
1990	73.293
1991	73.435
1992	73.602
1993	73.725
1994	73.755
1995	73.677
1996	73.496
1997	73.245
1998	72.924
1999	72.474
2000	72.253
2001	72.085
2002	72.015
2003	71.978
2004	72.104
2005	72.237
2006	72.415
2007	74.365
2008	72.756
2009	71.975
2010	71.57
2011	73.303
2012	73.626
2013	73.774
2014	74.907
2015	74.678
2016	76.121
2017	76.091
2018	76.058
2019	76.022
2020	75.985
2021	75.948
2022	75.914
2023	75.884
2024	75.856
2025	75.828
2026	75.799
2027	75.766
2028	75.73
2029	75.695
2030	75.664