How often do we get sick?

I was wondering how many times people fall sick in a year, falling sick as in getting a cold or the flu. I think generally, I fall really sick once a year, but my husband said he read an article saying that the average is once every five years. I don't think I can agree with that and went googling for information.

I couldn't find the article but this one is quite interesting: Why Some People Don't Get the Flu?

pearlie