condition mean min max ZT0-3 11870.477779 11870.477779 11870.477779 ZT4-7 9620.892221 9620.892221 9620.892221 ZT8-11 4058.250555333333 4058.250555333333 4058.250555333333 ZT12-15 573.6022222 573.6022222 573.6022222 ZT16-19 137.04444443333335 137.04444443333335 137.04444443333335 ZT20-23 1149.1522221 1149.1522221 1149.1522221