condition mean min max ZT0-3 2.95 2.95 2.95 ZT4-7 3.6 3.6 3.6 ZT8-11 1.95 1.95 1.95 ZT12-15 1.9500000000000002 1.9500000000000002 1.9500000000000002 ZT16-19 1.6 1.6 1.6 ZT20-23 2.75 2.75 2.75