condition mean min max ZT0-3 5.55 5.55 5.55 ZT4-7 2.4 2.4 2.4 ZT8-11 2.85 2.85 2.85 ZT12-15 13.399999999999999 13.399999999999999 13.399999999999999 ZT16-19 2.0 2.0 2.0 ZT20-23 7.55 7.55 7.55