And while we're on the topic: "Casualty" does not refer only to people who have died. It can be a serious or fatal accident. It can be a person or thing injured, lost, or destroyed. And it can mean a military person lost through death, wounds, injury, sickness, internment, or capture or through being missing in action.
What I'm getting at here is that you have to find a different word if you are talking about the number of soldiers who have died.