This file contains data tables representing gravitational wave backgrounds (GWBs) produced by Nambu-Goto cosmic strings evolved under numerical gravitational backreaction. The GWBs were produced using the methodology of "More accurate gravitational wave backgrounds from cosmic strings" [to appear], by the same authors as this dataset. The file is organized in three columns: The base-10 logarithm of the string coupling to gravity, G\mu. The range is from -8 to -22 in steps of -0.1. The frequency in Hz, f. The range is from 10^(-12) Hz to 10^5 Hz in multiplicative steps of 10^(0.01). The critical energy density fraction in gravitational waves scaled by the dimensionless Hubble constant squared, \Omega_{gw} h^2.