As an example, Fig. (1) shows the distributions of the index R for some N values. It appears that the distribution dispersion decreases if N increases and that the maximum moves to higher R values for larger proteins. With these data, it is possible to estimate the probability pR to have R values higher than a given value Rx, simply by integrating the probability density curve from Rx to 1, and, analogously, it is possible to get the statistical significance for the other indices. 