condition mean min max ZT0-3 20.192999999999998 20.192999999999998 20.192999999999998 ZT4-7 16.6741 16.6741 16.6741 ZT8-11 14.837499999999999 14.837499999999999 14.837499999999999 ZT12-15 17.22475 17.22475 17.22475 ZT16-19 26.855249999999998 26.855249999999998 26.855249999999998 ZT20-23 21.9178 21.9178 21.9178