condition mean min max ZT0-3 31.667749999999998 31.667749999999998 31.667749999999998 ZT4-7 27.497700000000002 27.497700000000002 27.497700000000002 ZT8-11 25.06475 25.06475 25.06475 ZT12-15 27.5588 27.5588 27.5588 ZT16-19 28.937350000000002 28.937350000000002 28.937350000000002 ZT20-23 28.598750000000003 28.598750000000003 28.598750000000003