condition mean min max ZT0-3 20.23755 19.1661 21.308999999999997 ZT4-7 15.78745 15.78745 15.78745 ZT8-11 22.51645 22.51645 22.51645 ZT12-15 0 0 0 ZT16-19 22.7993 22.7993 22.7993 ZT20-23 22.618850000000002 22.618850000000002 22.618850000000002