condition mean min max ZT0-3 11.05602712 8.627668814 13.484385426000001 ZT4-7 23.2448686225 21.600674325 24.88906292 ZT8-11 17.279602171 14.908838372 19.650365970000003 ZT12-15 2.0669382465 0.07745768349999999 4.0564188095 ZT16-19 0.20389668849999998 0.16358317 0.24421020699999998 ZT20-23 0.12791262425 0.09027347449999999 0.165551774