The series of papyrus and ostraca from Deir el-Medina recording fish deliveries during the Twentieth Dynasty constitute a large amount of homogeneous material suitable for a statistical analysis. We studied 186 data corresponding to a quantity of fish expressed in deben and delivered by a fisherman on a given day to the village of the royal tomb workers. A uni and multivariate analysis showed that fish deliveries fluctuated according to the size of the workmen gang. In addition, the Nile flood was probably responsible for intra-annual seasonal variations. A striking finding was a significant reduction of the amount of fish delivered at the end of the reign of Ramesses IX and under Ramesses X comparatively to the time of Ramesses III and IV. A series of abnormal Nile floods rather than social or economical factors may account for this phenomenon.