Year	Percent
1990	75.286
1991	75.236
1992	75.287
1993	75.385
1994	75.511
1995	75.742
1996	75.791
1997	75.946
1998	76.173
1999	76.434
2000	76.696
2001	76.901
2002	77.135
2003	77.378
2004	77.722
2005	78.122
2006	78.496
2007	78.896
2008	79.321
2009	79.753
2010	80.148
2011	80.835
2012	80.973
2013	81.345
2014	81.676
2015	81.79
2016	81.95
2017	82.035
2018	82.075
2019	82.065
2020	82.007
2021	81.918
2022	81.794
2023	81.638
2024	81.451
2025	81.238
2026	81.015
2027	80.774
2028	80.535
2029	80.33
2030	80.177