condition mean min max ZT0-3 1.334285 1.334285 1.334285 ZT4-7 0.8915204999999999 0.8915204999999999 0.8915204999999999 ZT8-11 0.6505525 0.6505525 0.6505525 ZT12-15 1.3044850000000001 1.3044850000000001 1.3044850000000001 ZT16-19 2.46814 2.46814 2.46814 ZT20-23 1.581105 1.581105 1.581105