condition mean min max ZT0-3 17.2 17.2 17.2 ZT4-7 3.1 3.1 3.1 ZT8-11 17.650000000000002 17.650000000000002 17.650000000000002 ZT12-15 19.85 19.85 19.85 ZT16-19 3.95 3.95 3.95 ZT20-23 12.45 12.45 12.45