Year	Percent
1990	77.634
1991	77.55
1992	77.49
1993	77.648
1994	77.616
1995	77.417
1996	77.666
1997	77.998
1998	78.214
1999	78.285
2000	78.321
2001	78.073
2002	77.832
2003	76.819
2004	75.747
2005	74.653
2006	73.766
2007	72.947
2008	72.172
2009	73.016
2010	71.759
2011	72.916
2012	74.035
2013	70.71
2014	72.533
2015	74.296
2016	74.404
2017	74.513
2018	74.685
2019	74.897
2020	75.128
2021	75.409
2022	75.713
2023	76.008
2024	76.245
2025	76.392
2026	76.476
2027	76.449
2028	76.332
2029	76.169
2030	75.998