condition mean min max ZT0-3 20.75 20.75 20.75 ZT4-7 13.6 13.6 13.6 ZT8-11 31.3 31.3 31.3 ZT12-15 10.399999999999999 10.399999999999999 10.399999999999999 ZT16-19 27.5 27.5 27.5 ZT20-23 14.65 14.65 14.65