Because this tells you something about the effectiveness of countermeasures. Which is something we need to learn as much about as possible.

Because it is obviously a competition between countries. "We managed to get through with less casualties then country X, so we are superior."

> with less[er] casualties than country X

Is that a subtle joke about mean body mass in the US, or a grammatical error? http://ddg.gg/?q=count+vs+mass+noun

Thanks for pointing me to english grammar lessons I couldn't care less about. Or is it lesser, whatever.

No, I wasn't trying to do a subtle joke about obese americans. But now that you inspire me, I will consider it in the future.