condition mean min max ZT0-3 39.2 39.2 39.2 ZT4-7 34.3 34.3 34.3 ZT8-11 20.15 20.15 20.15 ZT12-15 28.4 28.4 28.4 ZT16-19 27.549999999999997 27.549999999999997 27.549999999999997 ZT20-23 28.85 28.85 28.85