Variation in the $\frac{{\text{EW}}_{6614}}{\text{E}\left(\text{BP}-\text{RP}\right)}$ ratio with distance. Perseus is shown as black circles, Taurus as red circles, and Orion (combining Orion A and Orion B) as yellow squares. The full sample within 600 pc is represented by blue triangles and labeled as “ALL”. Sources are binned into 50 pc intervals. Error bars indicate the uncertainties in the fitted ratios for each distance bin.