condition mean min max ZT0-3 8.034267499999999 7.549049999999999 8.519485 ZT4-7 8.63132 8.63132 8.63132 ZT8-11 7.916285 7.916285 7.916285 ZT12-15 0 0 0 ZT16-19 9.83313 9.83313 9.83313 ZT20-23 12.568449999999999 12.568449999999999 12.568449999999999