condition mean min max ZT0-3 27.9693 21.236849999999997 34.03175 ZT4-7 17.60065 17.60065 17.60065 ZT8-11 20.2129 20.2129 20.2129 ZT12-15 25.166050000000002 23.621000000000002 26.711100000000002 ZT16-19 30.854950000000002 30.854950000000002 30.854950000000002 ZT20-23 38.631 38.631 38.631