I've heard so much mixed information about this that I'm not sure what to go with. How long, on average, would you say Pekins and Jumbo Pekins live? I'm not sure if mine are jumbo or not but they're probably 12-13 lbs at least each. One's so large its belly is almost scraping the ground. They WADDLE big time. I've heard estimates as low as 5 years and as high as 15 years. I know they're meat birds and not designed for longevity. What's been true for y'all?