Year	Percent
1990	78.792
1991	78.189
1992	77.655
1993	77.12
1994	76.503
1995	75.77
1996	75.094
1997	74.296
1998	73.595
1999	71.672
2000	69.58
2001	70.03
2002	70.555
2003	71.129
2004	71.71
2005	72.271
2006	72.842
2007	72.389
2008	71.949
2009	71.529
2010	68.334
2011	73.141
2012	76.778
2013	79.561
2014	79.533
2015	79.602
2016	79.64
2017	79.904
2018	80.149
2019	80.366
2020	80.548
2021	80.684
2022	80.793
2023	80.875
2024	80.924
2025	80.941
2026	80.913
2027	80.859
2028	80.797
2029	80.754
2030	80.744