condition mean min max ZT0-3 10.687122 10.687122 10.687122 ZT4-7 12.109922000000001 12.109922000000001 12.109922000000001 ZT8-11 11.0805985 11.0805985 11.0805985 ZT12-15 10.477438 10.477438 10.477438 ZT16-19 9.9207325 9.9207325 9.9207325 ZT20-23 10.2702675 10.2702675 10.2702675