condition mean min max ZT0-3 11.399999999999999 11.399999999999999 11.399999999999999 ZT4-7 0.9 0.9 0.9 ZT8-11 14.3 14.3 14.3 ZT12-15 15.200000000000001 15.200000000000001 15.200000000000001 ZT16-19 27.85 27.85 27.85 ZT20-23 22.650000000000002 22.650000000000002 22.650000000000002