Left panel: observed and predicted radial SFR density gradient relative to the solar neighbourhood. The model results are the big solid circles connected by a solid yellow line. The black line is the analytical form suggested by Green (2014) for the Milky Way SFR profile. The open circles with error bars are observational data from Rana (1991). Right panel: SFR evolution predicted by our best fit models computed at 4, 8, and 12 kpc. The dark green shaded area indicates the present-day measured range in the solar annulus by Prantzos et al. (2018).