condition mean min max ZT0-3 3.45 3.45 3.45 ZT4-7 35.5 35.5 35.5 ZT8-11 5.2 5.2 5.2 ZT12-15 15.05 15.05 15.05 ZT16-19 7.199999999999999 7.199999999999999 7.199999999999999 ZT20-23 15.5 15.5 15.5