Year	Percent
1990	67.496
1991	67.543
1992	67.535
1993	67.493
1994	67.268
1995	67.014
1996	66.849
1997	66.438
1998	66.047
1999	65.684
2000	65.432
2001	65.176
2002	64.943
2003	64.76
2004	62.614
2005	63.782
2006	66.266
2007	66.185
2008	67.655
2009	68.506
2010	68.634
2011	67.643
2012	67.387
2013	67.263
2014	67.982
2015	67.629
2016	67.726
2017	67.596
2018	67.434
2019	67.266
2020	67.106
2021	66.907
2022	66.719
2023	66.532
2024	66.327
2025	66.095
2026	65.805
2027	65.5
2028	65.183
2029	64.863
2030	64.546