Drop Size Distributions (DSDs) measured with an optical disdrometer in Madrid during 5 years are used to derive the copolar attenuation (CPA) and cross polarization discrimination (XPD) at 19.7 and 39.4 GHz. A full wave Method of Moments (MoM) is utilized to calculate specific attenuation and phase rotation through a realistic scattering raindrop model for large raindrops. The best-fit parameters are compared with those given in the ITU-R Recommendation P.618-12. Significant differences are observed for vertical and horizontal polarizations at 19.7 and 39.4 GHz. In this paper, yearly variability of XPD and fitting parameters are presented.