Year	Percent
1990	65.693
1991	64.609
1992	64.406
1993	63.886
1994	63.479
1995	63.142
1996	63.493
1997	63.171
1998	62.95
1999	63.075
2000	62.913
2001	62.57
2002	62.793
2003	62.837
2004	62.794
2005	62.553
2006	62.259
2007	62.117
2008	62.095
2009	62.127
2010	61.961
2011	61.543
2012	61.703
2013	61.435
2014	60.951
2015	60.704
2016	60.432
2017	60.119
2018	59.832
2019	59.56
2020	59.293
2021	59.024
2022	58.773
2023	58.537
2024	58.313
2025	58.102
2026	57.907
2027	57.731
2028	57.571
2029	57.419
2030	57.271