Let's talk box jumps!
Box jumps are a lower body (primarily) exercise used to build explosiveness, landing mechanics and force absorption. Box jumps are a valuable addition to any workout regimen, but they must be progressed according to fitness level, goals and experience.
In short, the average number of box jumps per workout should be 20-40 repetitions.
A person can do more or less, as this is by no means the law of the land.
This is my opinion deeply rooted in personal experience with athletes, my own training and my observation of modern evolution of box jumps.