Year	Percent
1990	77.017
1991	76.381
1992	75.755
1993	75.096
1994	74.329
1995	73.428
1996	73.011
1997	72.507
1998	71.964
1999	71.453
2000	71.022
2001	71.503
2002	72.258
2003	73.247
2004	74.402
2005	75.646
2006	76.514
2007	76.8
2008	77.27
2009	77.895
2010	78.622
2011	79.255
2012	79.995
2013	80.809
2014	81.639
2015	81.811
2016	81.685
2017	82.126
2018	82.503
2019	82.826
2020	83.093
2021	83.113
2022	83.061
2023	82.961
2024	82.83
2025	82.675
2026	82.388
2027	82.071
2028	81.754
2029	81.464
2030	81.217