Year	Percent
1990	78.065
1991	77.904
1992	76.923
1993	76.617
1994	76.205
1995	75.383
1996	75.84
1997	76.355
1998	77.004
1999	77.593
2000	78.569
2001	78.224
2002	78.993
2003	79.865
2004	80.204
2005	81.066
2006	81.36
2007	81.517
2008	81.799
2009	81.099
2010	80.949
2011	80.591
2012	80.33
2013	80
2014	79.779
2015	79.834
2016	79.526
2017	79.257
2018	78.939
2019	78.593
2020	78.236
2021	77.857
2022	77.467
2023	77.09
2024	76.76
2025	76.5
2026	76.294
2027	76.17
2028	76.106
2029	76.065
2030	76.019