I don't think it is on the rise. In the past I believe it was more under reported. When I ended up with (occasional) secondary nocturnal enuresis years (decades) ago, I felt the statistics out of Israel were probably more accurate than most due to required military service.... The tri-state incontinence support site hasn't been online for some time, or I'd add a pointer to their graph of incontinence vs age with male / female split. Don't know if that could be dug out of the way back (internet archives) machine.