condition mean min max ZT0-3 8.35 8.35 8.35 ZT4-7 2.8 2.8 2.8 ZT8-11 4.0 4.0 4.0 ZT12-15 2.0999999999999996 2.0999999999999996 2.0999999999999996 ZT16-19 15.95 15.95 15.95 ZT20-23 3.6 3.6 3.6