Year	Percent
1990	73.608
1991	73.834
1992	73.985
1993	74.084
1994	74.016
1995	73.924
1996	73.918
1997	73.665
1998	73.42
1999	73.188
2000	72.968
2001	72.778
2002	72.587
2003	72.619
2004	70.573
2005	71.715
2006	74.856
2007	74.829
2008	76.531
2009	77.585
2010	77.718
2011	76.888
2012	76.592
2013	76.737
2014	77.761
2015	77.354
2016	77.694
2017	77.964
2018	78.224
2019	78.477
2020	78.724
2021	78.97
2022	79.21
2023	79.432
2024	79.618
2025	79.756
2026	79.855
2027	79.906
2028	79.921
2029	79.924
2030	79.929