condition mean min max ZT0-3 14.55 14.55 14.55 ZT4-7 8.4 8.4 8.4 ZT8-11 24.25 24.25 24.25 ZT12-15 3.9499999999999997 3.9499999999999997 3.9499999999999997 ZT16-19 7.65 7.65 7.65 ZT20-23 10.8 10.8 10.8