condition mean min max ZT0-3 7.27344 7.27344 7.27344 ZT4-7 4.612995 4.612995 4.612995 ZT8-11 6.30381 6.30381 6.30381 ZT12-15 9.50687 9.50687 9.50687 ZT16-19 10.030625 10.030625 10.030625 ZT20-23 7.438174999999999 7.438174999999999 7.438174999999999