condition mean min max ZT0-3 2.56683 2.37761 2.75605 ZT4-7 2.071015 2.071015 2.071015 ZT8-11 2.326965 2.326965 2.326965 ZT12-15 0 0 0 ZT16-19 2.8536599999999996 2.8536599999999996 2.8536599999999996 ZT20-23 3.386845 3.386845 3.386845