condition mean min max ZT0-3 18.9 18.9 18.9 ZT4-7 17.6 17.6 17.6 ZT8-11 75.15 75.15 75.15 ZT12-15 12.05 12.05 12.05 ZT16-19 56.099999999999994 56.099999999999994 56.099999999999994 ZT20-23 33.65 33.65 33.65