condition mean min max ZT0-3 33.349999999999994 33.349999999999994 33.349999999999994 ZT4-7 22.3 22.3 22.3 ZT8-11 19.95 19.95 19.95 ZT12-15 25.9 25.9 25.9 ZT16-19 35.0 35.0 35.0 ZT20-23 15.25 15.25 15.25