condition mean min max ZT0-3 10.75 10.75 10.75 ZT4-7 6.5 6.5 6.5 ZT8-11 3.9499999999999997 3.9499999999999997 3.9499999999999997 ZT12-15 4.55 4.55 4.55 ZT16-19 3.4499999999999997 3.4499999999999997 3.4499999999999997 ZT20-23 15.1 15.1 15.1