The energy dependence of the cross section of incoherent \Jpsi photonuclear production off lead nuclei is shown for three different ranges of the Mandelstam-$t$ variable (left). The symbols denote the measured cross section, the vertical lines across them represent the uncorrelated uncertainty, the open boxes the correlated uncertainty, and the horizontal shadow box the uncertainty from the computation of the photon flux. Ratio of the cross sections at different Mandelstam-$t$ ranges (right) normalised such that the lower energy ratio is one. The vertical line denotes the statistical and \mant-uncorrelated systematic uncertainties added inquadrature. In the left panel the data symbols have been slightly displaced horizontally to improve their visibility.