condition mean min max ZT0-3 1.103964 1.103964 1.103964 ZT4-7 1.6065055 1.6065055 1.6065055 ZT8-11 1.275852 1.275852 1.275852 ZT12-15 1.705985 1.705985 1.705985 ZT16-19 0.7880119999999999 0.7880119999999999 0.7880119999999999 ZT20-23 0.938537 0.938537 0.938537