condition mean min max ZT0-3 28.700000000000003 28.700000000000003 28.700000000000003 ZT4-7 27.0 27.0 27.0 ZT8-11 51.400000000000006 51.400000000000006 51.400000000000006 ZT12-15 2.9 2.9 2.9 ZT16-19 14.200000000000001 14.200000000000001 14.200000000000001 ZT20-23 23.299999999999997 23.299999999999997 23.299999999999997