Year	Percent
1990	80.475
1991	80.657
1992	80.892
1993	81.154
1994	81.421
1995	81.68
1996	81.621
1997	81.582
1998	81.577
1999	81.622
2000	81.37
2001	81.088
2002	80.803
2003	80.512
2004	80.216
2005	79.912
2006	79.605
2007	79.289
2008	78.963
2009	79.282
2010	79.627
2011	80.233
2012	80.85
2013	81.428
2014	81.909
2015	82.284
2016	82.768
2017	82.726
2018	82.692
2019	82.671
2020	82.665
2021	82.669
2022	82.689
2023	82.721
2024	82.756
2025	82.791
2026	82.825
2027	82.862
2028	82.899
2029	82.929
2030	82.949