condition mean min max ZT0-3 12.3529 12.3529 12.3529 ZT4-7 10.06988 10.06988 10.06988 ZT8-11 11.79255 11.79255 11.79255 ZT12-15 13.50535 13.50535 13.50535 ZT16-19 13.371749999999999 13.371749999999999 13.371749999999999 ZT20-23 13.2799 13.2799 13.2799