Distribution matrix of relative bulk velocity offsets (δv), low-level energies (E_low), proton-electron sensitivity coefficients (K_μ), sky frequencies, and observation epochs, for observed methanol lines (Tables 2 and A.1). The Pearson r coefficients of the correlation matrix are given between the different variables. The data points corresponding to A-CH₃OH and E-CH₃OH transitions are marked with red crosses and blue squares, respectively. Those of ¹³CH₃OH are indicated with green circles. The best results of the multivariate linear regression fit between the v_i, time, E_low, and K_μ (see Table 3) are shown in the corresponding panels.