Year	Percent
1990	82.485
1991	80.923
1992	80.944
1993	80.239
1994	80.663
1995	81.086
1996	82.54
1997	84.322
1998	84.925
1999	84.158
2000	84.517
2001	84.006
2002	83.326
2003	81.826
2004	81.298
2005	81.123
2006	81.261
2007	81.647
2008	82.688
2009	81.138
2010	80.465
2011	79.76
2012	80.347
2013	80.018
2014	79.877
2015	80.259
2016	80.029
2017	80.001
2018	79.984
2019	79.971
2020	79.956
2021	79.891
2022	79.814
2023	79.737
2024	79.675
2025	79.638
2026	79.579
2027	79.541
2028	79.52
2029	79.504
2030	79.482