Not many BHP are getting that big unless they're being overfed and that's a big no no for this species. You need to keep them on the leaner side to keep them healthy longterm so most will stay closer to the 6-7 foot range. Feeding small and/or leaner meals more often seems to be a major key to successfully rearing these critters. Nothing is quite as fun as feeding a hungry BHP either. Every bit as crazy as my craziest colubrids, haha.