Predicted Type Ia SN rates for the different DTDs considered in this work (see Fig. 1) assuming the one-infall model introduced in Sect. 3.2. The area in the vertical axis refers to that of the Galactic disc region (3 kpc < R < 20 kpc). The rates are expressed in SN events per century and normalized (through the C_Ia) to reproduce the present time Type Ia SN rate in the Milky Way (Li et al. 2011, filled red circle and error bar).