condition mean min max ZT0-3 230.715333 230.715333 230.715333 ZT4-7 232.10508400000003 232.10508400000003 232.10508400000003 ZT8-11 272.76943600000004 272.76943600000004 272.76943600000004 ZT12-15 257.953098 257.953098 257.953098 ZT16-19 252.43058200000002 252.43058200000002 252.43058200000002 ZT20-23 237.86931099999998 237.86931099999998 237.86931099999998