condition mean min max ZT0-3 34.9 34.9 34.9 ZT4-7 39.8 39.8 39.8 ZT8-11 21.0 21.0 21.0 ZT12-15 54.099999999999994 54.099999999999994 54.099999999999994 ZT16-19 15.15 15.15 15.15 ZT20-23 33.85 33.85 33.85