condition mean min max ZT0-3 2.9727316666666668 1.80643 3.86683 ZT4-7 1.9960749999999998 1.9960749999999998 1.9960749999999998 ZT8-11 2.32855 2.32855 2.32855 ZT12-15 4.4562925 3.2739700000000003 5.638615 ZT16-19 5.22677 5.22677 5.22677 ZT20-23 4.391245 4.391245 4.391245