condition mean min max ZT0-3 156.907316 156.907316 156.907316 ZT4-7 210.115776 210.115776 210.115776 ZT8-11 134.500455 134.500455 134.500455 ZT12-15 126.2858925 126.2858925 126.2858925 ZT16-19 114.498917 114.498917 114.498917 ZT20-23 139.4287615 139.4287615 139.4287615