Year	Percent
1990	64.883
1991	64.81
1992	64.667
1993	64.579
1994	64.485
1995	64.333
1996	64.303
1997	64.184
1998	64.027
1999	63.94
2000	63.868
2001	63.876
2002	63.789
2003	63.785
2004	63.739
2005	63.684
2006	63.495
2007	63.247
2008	63.182
2009	63.289
2010	63.245
2011	63.12
2012	66.37
2013	57.2
2014	57.41
2015	58.58
2016	57.76
2017	57.614
2018	57.468
2019	57.322
2020	57.177
2021	57.031
2022	56.885
2023	56.739
2024	56.593
2025	56.447
2026	56.301
2027	56.155
2028	56.01
2029	55.864
2030	55.718