condition mean min max ZT0-3 7.50155 7.50155 7.50155 ZT4-7 4.9532799999999995 4.9532799999999995 4.9532799999999995 ZT8-11 7.06786 7.06786 7.06786 ZT12-15 9.267890000000001 9.267890000000001 9.267890000000001 ZT16-19 11.56405 11.56405 11.56405 ZT20-23 8.727275 8.727275 8.727275