Year	Percent
1990	80.297
1991	80.208
1992	80.151
1993	80.13
1994	80.074
1995	79.926
1996	78.521
1997	78.365
1998	78.236
1999	76.085
2000	75.201
2001	73.556
2002	72.604
2003	75.353
2004	73.988
2005	73.478
2006	76.221
2007	77.758
2008	78.543
2009	77.883
2010	76.928
2011	78.201
2012	78.495
2013	78.686
2014	79.42
2015	80.518
2016	81.956
2017	81.904
2018	81.75
2019	81.516
2020	81.22
2021	80.869
2022	80.441
2023	79.982
2024	79.569
2025	79.25
2026	79.038
2027	78.937
2028	78.906
2029	78.873
2030	78.794