condition mean min max ZT0-3 27.95 27.95 27.95 ZT4-7 4.4 4.4 4.4 ZT8-11 28.450000000000003 28.450000000000003 28.450000000000003 ZT12-15 15.45 15.45 15.45 ZT16-19 13.4 13.4 13.4 ZT20-23 19.849999999999998 19.849999999999998 19.849999999999998