condition mean min max ZT0-3 13.844453 13.844453 13.844453 ZT4-7 15.382963 15.382963 15.382963 ZT8-11 15.518127 15.518127 15.518127 ZT12-15 13.49165 13.49165 13.49165 ZT16-19 15.0262685 15.0262685 15.0262685 ZT20-23 15.140979999999999 15.140979999999999 15.140979999999999