Distribution and kinematics of the atomic (blue filled squares) and CO-bright molecular (brown empty circles) hydrogen in the inner disc of the Milky Way, as derived from our modelling. The panels show the profiles for the rotation velocity (a), surface density (b), velocity dispersion (c), midplane density (d) and HWHM scale height (e). Each profile is smoothed to the resolution of 0.2 kpc. One point per resolution element is plotted. Error-bars show the 1σ uncertainty on the measurements, and account for both the approaching-receding asymmetry and the MCMC error-bars derived via our fitting technique (see the text for details). An additional 30% error on the H₂ midplane and surface densities is included to account for the uncertainties in the X_CO-factor (Bolatto et al. 2013). An ad-hoc 40 pc error is assumed for the scale height at R > 7 kpc.