condition mean min max ZT0-3 15.16455 15.16455 15.16455 ZT4-7 15.38605 15.38605 15.38605 ZT8-11 15.5347 15.5347 15.5347 ZT12-15 18.01015 18.01015 18.01015 ZT16-19 19.62825 19.62825 19.62825 ZT20-23 15.95995 15.95995 15.95995