Histograms of HCN J =1−0 HFS (a) Line intensity ratios, and (b) Line-width ratios observed in OrionB. R₀₂ stands for W(F = 0−1)/W(F = 2−1) and R₁₂ stands for W(F = 1–1)/W(F = 2−1). The red curve in panel (a) shows the expected LTE ratios as line opacities increase. The red star marks the non-anomalous ratios in the optically thin limit τ → 0 (1σ is the standard deviation relative to the mean line ratios).