condition mean min max ZT0-3 2.3730700000000002 2.3730700000000002 2.3730700000000002 ZT4-7 1.040838 1.040838 1.040838 ZT8-11 1.45623 1.45623 1.45623 ZT12-15 3.07522 3.07522 3.07522 ZT16-19 3.06152 3.06152 3.06152 ZT20-23 3.5414849999999998 3.5414849999999998 3.5414849999999998