prvol = IF(BARPERCENT > 0.05, VOLUME / BARPERCENT, VOLUME[-1]);

// Plot the pro-rated volume bar.
PLOT_HISTOGRAM(IF(INDEX >= COUNT - 1, prvol, NIL), 0.9, COLOR.Yellow);

// Plot the real volume.
PLOT_HISTOGRAM(VOLUME, 0.7, IF(CLOSE >= OPEN, COLOR("#F08080"), COLOR("#696969")));

// Summary.
SUMMARY("PRVOL: {?:F0}  VOL: {?} ({?:F0}%)", IF(INDEX >= COUNT - 1, prvol, "-"), VOLUME, 100 * BARPERCENT);