Distribution of possible polarization values for each GRB. The histograms are constructed using all possible permutations of the eight flux values measured for that GRB and have equal bin size P = 1%. The data are corrected for both instrumental polarization and depolarization. The vertical (blue) line indicates the measured value for the GRB. The normalized rank (R) of the GRB within the distribution is indicated. For sources with ﹩R\lt 0.9﹩ we conclude that the measured flux values are consistent with zero polarization and use the maximum permutated value to derive an upper limit.