condition mean min max ZT0-3 13.564096385500001 13.151662921 13.97652985 ZT4-7 7.1327725825 6.219014218 8.046530947 ZT8-11 20.201864378499998 15.702531486999998 24.70119727 ZT12-15 25.959468165 24.29490962 27.624026710000003 ZT16-19 20.511173812499997 20.059618785 20.962728839999997 ZT20-23 19.655949845 17.7066065 21.605293189999998