Year	Percent
1990	80.882
1991	81.049
1992	80.13
1993	80.972
1994	80.189
1995	80.556
1996	80.598
1997	79.463
1998	79.204
1999	79.252
2000	79.132
2001	79.084
2002	78.21
2003	78.836
2004	80.198
2005	79.88
2006	79.865
2007	79.313
2008	78.289
2009	78.122
2010	77.836
2011	77.395
2012	77.866
2013	77.889
2014	77.847
2015	76.688
2016	77.308
2017	77.413
2018	77.482
2019	77.542
2020	77.586
2021	77.659
2022	77.663
2023	77.647
2024	77.639
2025	77.639
2026	77.756
2027	77.823
2028	77.847
2029	77.843
2030	77.829