Year	Percent
1990	93.343
1991	93.32
1992	93.091
1993	92.837
1994	92.529
1995	92.153
1996	91.739
1997	91.268
1998	90.76
1999	90.245
2000	89.735
2001	89.2
2002	86.903
2003	86.274
2004	87.491
2005	86.287
2006	85.471
2007	87.5
2008	86.907
2009	84.594
2010	84.163
2011	85.459
2012	85.224
2013	84.71
2014	86.653
2015	86.972
2016	85.219
2017	85.181
2018	85.133
2019	85.066
2020	84.977
2021	84.872
2022	84.739
2023	84.588
2024	84.436
2025	84.295
2026	84.174
2027	84.072
2028	83.982
2029	83.892
2030	83.792