condition mean min max ZT0-3 15.35 15.35 15.35 ZT4-7 12.4 12.4 12.4 ZT8-11 8.45 8.45 8.45 ZT12-15 15.399999999999999 15.399999999999999 15.399999999999999 ZT16-19 11.899999999999999 11.899999999999999 11.899999999999999 ZT20-23 15.3 15.3 15.3