condition mean min max ZT0-3 5.6 5.6 5.6 ZT4-7 12.9 12.9 12.9 ZT8-11 8.899999999999999 8.899999999999999 8.899999999999999 ZT12-15 14.95 14.95 14.95 ZT16-19 27.45 27.45 27.45 ZT20-23 3.65 3.65 3.65