Current neutrino detectors are approaching a sensitivity that allows one to detect Active Galactic Nuclei (AGN) in their high state. However, the expected signals might be too weak to result in a significant detection. One possibility to increase the detection chance is to focus the searches during states of high electromagnetic activity, especially in the very high energy (VHE) gamma-ray regime. In this context a good knowledge of the phenomenology of gamma-ray flux variability of the known VHE AGN is crucial. Here, we present our effort in archiving and combining VHE gamma-ray lightcurves and first results including a lightcurve of Mrk 421 spanning 15 years and the estimation of an average observed high state rate.