condition mean min max ZT0-3 28.75 28.75 28.75 ZT4-7 76.5 76.5 76.5 ZT8-11 52.65 52.65 52.65 ZT12-15 80.8 80.8 80.8 ZT16-19 21.549999999999997 21.549999999999997 21.549999999999997 ZT20-23 33.5 33.5 33.5