condition mean min max ZT0-3 6.576775 6.576775 6.576775 ZT4-7 7.7047550000000005 7.7047550000000005 7.7047550000000005 ZT8-11 4.46498 4.46498 4.46498 ZT12-15 5.998189999999999 5.998189999999999 5.998189999999999 ZT16-19 7.847585 7.847585 7.847585 ZT20-23 10.471025000000001 10.471025000000001 10.471025000000001