condition mean min max ZT0-3 9.570331666666666 7.6952549999999995 10.57775 ZT4-7 6.2219549999999995 6.2219549999999995 6.2219549999999995 ZT8-11 4.11581 4.11581 4.11581 ZT12-15 5.5603125 4.838865 6.28176 ZT16-19 6.6529799999999994 6.6529799999999994 6.6529799999999994 ZT20-23 8.941949999999999 8.941949999999999 8.941949999999999