condition mean min max ZT0-3 319.334082 319.334082 319.334082 ZT4-7 220.454516 220.454516 220.454516 ZT8-11 245.21353449999998 245.21353449999998 245.21353449999998 ZT12-15 297.48072249999996 297.48072249999996 297.48072249999996 ZT16-19 444.577321 444.577321 444.577321 ZT20-23 388.3474415 388.3474415 388.3474415