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Annual Total Returns- Vanguard Extended Duration Treasury Index Fund (Institutional) [BarChart] - Institutional - Vanguard Extended Duration Treasury Index Fund - Institutional Shares
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
Total 10.28% 55.79% 3.25% (20.89%) 45.66% (4.43%) 1.53% 13.52% (3.49%) 19.16%