condition mean min max ZT0-3 80.425802 80.425802 80.425802 ZT4-7 159.8053125 159.8053125 159.8053125 ZT8-11 270.569857 270.569857 270.569857 ZT12-15 265.59997999999996 265.59997999999996 265.59997999999996 ZT16-19 320.210611 320.210611 320.210611 ZT20-23 150.2345375 150.2345375 150.2345375