condition mean min max ZT0-3 750.577868 750.577868 750.577868 ZT4-7 569.963468 569.963468 569.963468 ZT8-11 529.339122 529.339122 529.339122 ZT12-15 547.950252 547.950252 547.950252 ZT16-19 818.1903335 818.1903335 818.1903335 ZT20-23 902.360212 902.360212 902.360212