condition mean min max ZT0-3 22.134257 22.134257 22.134257 ZT4-7 23.240606999999997 23.240606999999997 23.240606999999997 ZT8-11 23.1772375 23.1772375 23.1772375 ZT12-15 26.300537499999997 26.300537499999997 26.300537499999997 ZT16-19 28.1513305 28.1513305 28.1513305 ZT20-23 26.1068855 26.1068855 26.1068855