Happier?

On the news this morning there was a report on happiness. It compared couples without children to those who had kids. The findings were that childless couples as a whole were 7% happier than those with kids. I can't imagine this. My life is so much better with kids in it. Maybe the couples with children have more stress, worry, work, financial responsibilities, etc. But that is nothing in comparison to the satisfaction, joy, love, blessings, fulfillment and on and on that kids bring into one's life.
I think the couples that were tested must have been the ones who had no desire for children in the first place. Those who are satisfied with things how they are. Before my kids came along I wanted them so much. Any opinions out there?