Year	Percent
1990	67.693
1991	68.108
1992	68.393
1993	68.586
1994	68.719
1995	68.737
1996	68.739
1997	68.724
1998	68.547
1999	68.627
2000	68.49
2001	68.458
2002	68.503
2003	68.586
2004	68.592
2005	68.506
2006	67.979
2007	67.25
2008	66.47
2009	65.825
2010	64.969
2011	64.1
2012	64.821
2013	64.642
2014	64.504
2015	64.406
2016	64.414
2017	64.401
2018	64.423
2019	64.427
2020	64.383
2021	64.317
2022	64.204
2023	64.07
2024	63.961
2025	63.901
2026	63.904
2027	63.95
2028	64.015
2029	64.057
2030	64.054