Year	Percent
1990	82.523
1991	82.511
1992	82.456
1993	82.385
1994	82.217
1995	82.077
1996	81.923
1997	81.756
1998	81.567
1999	81.349
2000	81.102
2001	80.892
2002	80.646
2003	80.371
2004	80.082
2005	79.793
2006	79.632
2007	79.491
2008	79.38
2009	79.318
2010	79.313
2011	79.335
2012	79.395
2013	79.445
2014	79.521
2015	79.569
2016	79.561
2017	79.706
2018	79.831
2019	79.923
2020	79.974
2021	79.995
2022	79.981
2023	79.94
2024	79.89
2025	79.841
2026	79.804
2027	79.771
2028	79.739
2029	79.702
2030	79.657