Crater statistics based on size frequency distribution have been correlated with the age of planets' surfaces. We propose to widen statistical analysis of craters using not only diameter but also crater depths. We briefly present a calibrated method that quickly measures the depth of craters and provide a dataset that is large enough to perform statistical analyses. We use this method to study the evolution for depth of several secondary clusters of the Martian crater Mojave. Our method shows that the depth to diameter ratio (D/d) is not constant but varies with the diameter. This brings a new perspective on crater depth distribution.