condition mean min max ZT0-3 13.2 13.2 13.2 ZT4-7 19.0 19.0 19.0 ZT8-11 12.399999999999999 12.399999999999999 12.399999999999999 ZT12-15 30.75 30.75 30.75 ZT16-19 21.9 21.9 21.9 ZT20-23 30.6 30.6 30.6