condition mean min max ZT0-3 15.388499999999999 14.7915 15.985499999999998 ZT4-7 18.17705 18.17705 18.17705 ZT8-11 18.915 18.915 18.915 ZT12-15 0 0 0 ZT16-19 25.4387 25.4387 25.4387 ZT20-23 19.078699999999998 19.078699999999998 19.078699999999998