Year	Percent
1990	66.92
1991	66.869
1992	66.833
1993	66.794
1994	66.753
1995	66.801
1996	66.833
1997	66.868
1998	66.962
1999	67.045
2000	67.211
2001	67.31
2002	67.432
2003	67.549
2004	67.695
2005	67.872
2006	68.037
2007	68.163
2008	68.339
2009	68.524
2010	68.708
2011	68.772
2012	68.799
2013	68.789
2014	68.773
2015	68.711
2016	68.625
2017	68.571
2018	68.506
2019	68.428
2020	68.337
2021	68.25
2022	68.158
2023	68.072
2024	68.001
2025	67.951
2026	67.927
2027	67.921
2028	67.937
2029	67.98
2030	68.052