condition mean min max ZT0-3 12.399999999999999 12.399999999999999 12.399999999999999 ZT4-7 2.8 2.8 2.8 ZT8-11 5.3 5.3 5.3 ZT12-15 7.0 7.0 7.0 ZT16-19 29.9 29.9 29.9 ZT20-23 11.149999999999999 11.149999999999999 11.149999999999999