Figure further explores the difference in quantification accuracy between small (≤ 1 kg/hr) and large (> 1 kg/hr) emissions. Subfigures (a) and (b) show histograms of the percent difference between estimated and true rates for small and large emissions, respectively. Estimates for small emissions tend to underestimate, with an average percent difference of -3.9%. Note, however, that the median percent difference is -28.9% and 68.6% of the estimates underestimate the true rate. This means that underestimation is more common than overestimation for small emissions, but overestimation error is larger than underestimation error on average. Estimates for large emissions tend to overestimate, with an average percent difference of 4.3%. In this regime, the median percent difference is -2.3% and 53.5% of the estimates underestimate the true rate. This means that over and underestimation are nearly equally likely for large emissions, with overestimation error being only slightly larger than underestimation error on average. For small emissions (≤ 1 kg/hr), 90% of the estimates have error within a percent difference of .2%] or a factor difference of [-4.0, 3.0] from the true rate. Performance is markedly better for large emissions (> 1 kg/hr), where 90% of the estimates have error within a percent difference of .8%] or a factor difference of ] from the true rate. Note that percent difference is calculated as the estimated rate minus the true rate divided by the true rate. Factor difference is calculated as the estimated rate divided by the true rate for instances where the estimated rate is larger than the true rate and as the true rate divided by the estimated rate for instances where the estimated rate is smaller than the true rate.