condition mean min max ZT0-3 3.2085333333333335 2.915395 3.75589 ZT4-7 3.49066 3.49066 3.49066 ZT8-11 1.969735 1.969735 1.969735 ZT12-15 1.16012825 0.6960314999999999 1.624225 ZT16-19 2.2614 2.2614 2.2614 ZT20-23 2.715325 2.715325 2.715325