Longitudinal distance histograms (top row) of RHESSI flares with |λ_F| ≤ 60° from the HSB PFSS, for solar Cycle 23 and 24 (left and right columns). With red, the change in polarity from positive to negative and blue from negative to positive. Cumulative distributions of these histograms (bottom row), with additional cumulative distributions over-plotted that were produced from a set of flares with longitudes drawn from a random distribution (pink for change in polarity from positive to negative and light blue for change in polarity from negative to positive).