condition mean min max ZT0-3 2.390575 2.390575 2.390575 ZT4-7 1.695365 1.695365 1.695365 ZT8-11 2.54996 2.54996 2.54996 ZT12-15 2.433535 2.433535 2.433535 ZT16-19 2.9784100000000002 2.9784100000000002 2.9784100000000002 ZT20-23 2.3857749999999998 2.3857749999999998 2.3857749999999998