Histograms of the count of RPC-MIP cold electron signatures (blue bars), the count of derived RPC-MIP electron densities (red bars) and the total count of mutual impedance spectra acquired in the phased SDL sub-mode (black bars) compared to the sine of the latitude (top panels) and the longitude expressed in degrees (bottom panels). The cold-to-acquired ratio is shown in yellow squares. Left panels: from 2015 Sept. 4 to 2016 May 21 corresponding to the southern (resp. northern) hemisphere in summer (resp. winter). Right panels: from 2016 May 22 to 2016 Sept. 2016 corresponding to the southern (resp. northern) hemisphere in autumn (resp. spring).