condition mean min max ZT0-3 643.983786 643.983786 643.983786 ZT4-7 566.0075105000001 566.0075105000001 566.0075105000001 ZT8-11 438.2155505 438.2155505 438.2155505 ZT12-15 484.372486 484.372486 484.372486 ZT16-19 583.566041 583.566041 583.566041 ZT20-23 672.5753924999999 672.5753924999999 672.5753924999999