condition mean min max ZT0-3 4.237515 4.21863 4.256399999999999 ZT4-7 3.67673 3.67673 3.67673 ZT8-11 9.26341 9.26341 9.26341 ZT12-15 0 0 0 ZT16-19 8.453345 8.453345 8.453345 ZT20-23 5.809995 5.809995 5.809995