Year	Percent
1990	80.831
1991	81.094
1992	81.712
1993	79.909
1994	79.607
1995	82.201
1996	81.526
1997	80.77
1998	81.956
1999	82.301
2000	83.044
2001	83.624
2002	82.097
2003	81.812
2004	81.352
2005	80.686
2006	81.748
2007	81.893
2008	81.207
2009	78.985
2010	79.135
2011	78.385
2012	77.847
2013	78.699
2014	80.391
2015	80.946
2016	82.311
2017	81.785
2018	81.243
2019	80.68
2020	80.093
2021	79.493
2022	78.882
2023	78.268
2024	77.66
2025	77.061
2026	76.491
2027	75.933
2028	75.388
2029	74.853
2030	74.328