condition mean min max ZT0-3 29.978212 29.978212 29.978212 ZT4-7 41.175431 41.175431 41.175431 ZT8-11 51.58962 51.58962 51.58962 ZT12-15 48.560557 48.560557 48.560557 ZT16-19 30.488118 30.488118 30.488118 ZT20-23 27.984701 27.984701 27.984701