Results of the Gaussian mixture modeling (GMM) given as , where <i>m</i>_<i>i</i>, <i>s</i>_<i>i</i> and <i>w</i>_<i>i</i> are the parameters mean, standard deviation and relative weight of each of the Gaussians, respectively, obtained for the <i>UGini</i> index data.

The final model with an optimum number of M = 4 mixes was selected on the basis of the Akaike information criterion [26], visual inspection of the fit, the statistical significance of an χ2 test estimating the likelihood that the final model did not adequately describe the data, and a quantile-quantile plot (Fig 5).