condition mean min max ZT0-3 17.4264 15.45635 19.39645 ZT4-7 10.66505 10.66505 10.66505 ZT8-11 10.77385 10.77385 10.77385 ZT12-15 0 0 0 ZT16-19 13.73135 13.73135 13.73135 ZT20-23 15.81085 15.81085 15.81085