condition mean min max ZT0-3 3.55 3.55 3.55 ZT4-7 3.0 3.0 3.0 ZT8-11 4.300000000000001 4.300000000000001 4.300000000000001 ZT12-15 2.5 2.5 2.5 ZT16-19 6.95 6.95 6.95 ZT20-23 4.25 4.25 4.25