Histograms of values of Q in the mid-plane, at (a) t = 200, (b) t = 325, and (c) t = 400; and scatter plots showing the distribution of values of Q and ∫ E_∥ ds at the same point in the mid-plane, at (d) t = 200, (e) t = 325, and (f) t = 400. In order to represent the full distribution on a single set of axes, the histograms are produced with frequency density (the vertical axis) and Q (the horizontal axis) each on a logarithmic scale. The blue bars indicate the distribution where ∫ E_∥ ds = 0, and the red that where ∫ E_∥ ds ≠ 0. The histograms are normalized such that the two histograms for each time have a combined area of unity. The scatter plots are also produced on a logarithmic scale.