condition mean min max ZT0-3 16.65 16.65 16.65 ZT4-7 6.7 6.7 6.7 ZT8-11 21.9 21.9 21.9 ZT12-15 15.399999999999999 15.399999999999999 15.399999999999999 ZT16-19 47.1 47.1 47.1 ZT20-23 37.2 37.2 37.2