condition mean min max ZT0-3 1.7000000000000002 1.7000000000000002 1.7000000000000002 ZT4-7 3.9 3.9 3.9 ZT8-11 4.35 4.35 4.35 ZT12-15 2.35 2.35 2.35 ZT16-19 5.5 5.5 5.5 ZT20-23 19.75 19.75 19.75