Top: comparison of the fractional polarization (ratio of polarized flux density to total intensity) at 150 MHz (our catalog, vertical axis) and 1.4 GHz (Taylor et al. (2009) catalog, horizontal axis), for the 51 sources present in both catalogs. The black line marks 1:1 equivalence. Bottom: histogram of the depolarization ratio, which is defined as the ratio of 150 MHz fractional polarization to 1.4 GHz fractional polarization, for the same sources.