condition mean min max ZT0-3 11.399999999999999 11.399999999999999 11.399999999999999 ZT4-7 5.5 5.5 5.5 ZT8-11 25.3 25.3 25.3 ZT12-15 3.3 3.3 3.3 ZT16-19 5.699999999999999 5.699999999999999 5.699999999999999 ZT20-23 4.6 4.6 4.6