condition mean min max ZT0-3 2.5999999999999996 2.5999999999999996 2.5999999999999996 ZT4-7 2.6 2.6 2.6 ZT8-11 22.299999999999997 22.299999999999997 22.299999999999997 ZT12-15 5.25 5.25 5.25 ZT16-19 6.7 6.7 6.7 ZT20-23 10.8 10.8 10.8