Year	Percent
1990	65.972
1991	66.086
1992	66.743
1993	66.784
1994	66.629
1995	66.556
1996	66.585
1997	66.65
1998	66.229
1999	66.543
2000	66.92
2001	66.934
2002	67.153
2003	67.188
2004	67.554
2005	67.619
2006	67.683
2007	67.883
2008	67.65
2009	68.053
2010	67.842
2011	68.06
2012	67.641
2013	67.596
2014	67.414
2015	67.43
2016	67.407
2017	67.468
2018	67.529
2019	67.591
2020	67.652
2021	67.714
2022	67.775
2023	67.837
2024	67.898
2025	67.96
2026	68.021
2027	68.083
2028	68.144
2029	68.206
2030	68.267