The relationship between self-reported volume (x-axis) and individual (Figure 3) or aggregated (Figure 4) volume estimated from the Widmark equation can be seen in Figure 3 and Figure 4. In addition, the fractional polynomial fit to the data in each graph is shown as the solid line. For the individual and aggregate level data in Figure 3 and Figure 4, the R2 for the fractional polynomial fit to the data is .06 and .59, respectively.
