2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/104586We argue that the energy dependence of the average position of the shower maximum, $\bar X_{max}$, and of the number of produced muons, $N_μ$, can be explained by a change, around $10^{17}$eV, in the energy dependence of the inelasticity $K$, which decreases with the energy above the string percolation threshold.8 pages, 4 figures (6 eps files), latexHigh Energy Physics - PhenomenologyPercolation and cosmic ray physics above $10^{17}$eVtext