Comparison between the SFR on the leading and on the trailing edge of the bar. The black solid line shows a hypothetical one-to-one correlation. The data suggest a linear correlation that was tested with the Pearson correlation coefficient that yields ρ = 0.96 ± 0.01. The violet solid line shows a linear regression of the form y = m ⋅ x + c with the parameter estimates m = 0.58 ± 0.09 and c = 0.00 ± 0.01. On average, the SFR is stronger on the leading edge of the bar by a factor of 1.76.