condition mean min max ZT0-3 1.999855 1.8130950000000001 2.1866149999999998 ZT4-7 3.2394249999999998 3.2394249999999998 3.2394249999999998 ZT8-11 3.1741200000000003 3.1741200000000003 3.1741200000000003 ZT12-15 0 0 0 ZT16-19 1.45903 1.45903 1.45903 ZT20-23 2.40974 2.40974 2.40974