condition mean min max ZT0-3 34.229622 34.229622 34.229622 ZT4-7 30.635655 30.635655 30.635655 ZT8-11 30.240943 30.240943 30.240943 ZT12-15 28.559207 28.559207 28.559207 ZT16-19 29.625140000000002 29.625140000000002 29.625140000000002 ZT20-23 29.0198875 29.0198875 29.0198875