condition mean min max ZT0-3 4.15 4.15 4.15 ZT4-7 5.4 5.4 5.4 ZT8-11 7.75 7.75 7.75 ZT12-15 1.7999999999999998 1.7999999999999998 1.7999999999999998 ZT16-19 4.95 4.95 4.95 ZT20-23 2.75 2.75 2.75