What is there to explain? This statistic says something about the military capability.

What do you believe it says? I think by total numbers underline that the side with more military capability does show restraint. Most conflicts are way shorter with way more deaths.

Since 2000 there were over 10,000 rockets fired at Israel. It is not because of the lack of trying that casualties in Israel are that low.

It also shows that if the forceful response is meant to make the attacker learn, it's not working. Israel has made forceful responses for decades, and it didn't change a thing.