condition mean min max ZT0-3 20.937833333333334 15.9145 23.9477 ZT4-7 13.3991 13.3991 13.3991 ZT8-11 33.95855 33.95855 33.95855 ZT12-15 55.047875000000005 53.085 57.01075 ZT16-19 44.378600000000006 44.378600000000006 44.378600000000006 ZT20-23 32.494 32.494 32.494