condition mean min max ZT0-3 4.0 4.0 4.0 ZT4-7 4.2 4.2 4.2 ZT8-11 4.3 4.3 4.3 ZT12-15 18.85 18.85 18.85 ZT16-19 20.55 20.55 20.55 ZT20-23 11.399999999999999 11.399999999999999 11.399999999999999