condition mean min max ZT0-3 12.643527 12.643527 12.643527 ZT4-7 13.7271415 13.7271415 13.7271415 ZT8-11 11.633448000000001 11.633448000000001 11.633448000000001 ZT12-15 14.142566500000001 14.142566500000001 14.142566500000001 ZT16-19 10.7700345 10.7700345 10.7700345 ZT20-23 11.579638 11.579638 11.579638