condition mean min max ZT0-3 22.747253 22.747253 22.747253 ZT4-7 21.5155925 21.5155925 21.5155925 ZT8-11 16.140213000000003 16.140213000000003 16.140213000000003 ZT12-15 17.8570515 17.8570515 17.8570515 ZT16-19 14.6211505 14.6211505 14.6211505 ZT20-23 14.202998000000001 14.202998000000001 14.202998000000001