condition mean min max ZT0-3 2.9 2.9 2.9 ZT4-7 1.5 1.5 1.5 ZT8-11 4.95 4.95 4.95 ZT12-15 5.949999999999999 5.949999999999999 5.949999999999999 ZT16-19 2.2 2.2 2.2 ZT20-23 1.35 1.35 1.35