These are confirmed victims only, who could be identified by their ID number. The Gaza Ministry of Health has taken incredibly detailed statistics for years. They hire people whose only job is to count people, their injuries, details like location of bullet wounds, percent of successful and unsuccessful treatment, etc. Mind you this is in a completely hectic scenario / triage going on with hospitals overflowing with patients. There are WHO reports using this data for some of the past notable dates and they are always horrific.