We provide here calculated data based on the fits presented in the paper (file fits.xls) and fit parameters (file parameter.xls) of all samples (for 310K, they are shown in figure 1). In the excel-file fits.xls, each sheet contains the spectrum for a specific temperature and HCT value as is noted in the name of the sheet. In parameter.xls, the different sheets contain the fit parameters of the beta- and gamma-relaxation for different HCT values. For fitting the beta and gamma relaxations, Cole-Cole functions were used. In addition, a conductivity contribution, termed "sigma_dc" was used.