condition mean min max ZT0-3 5.85 5.85 5.85 ZT4-7 20.4 20.4 20.4 ZT8-11 16.400000000000002 16.400000000000002 16.400000000000002 ZT12-15 6.15 6.15 6.15 ZT16-19 11.399999999999999 11.399999999999999 11.399999999999999 ZT20-23 23.099999999999998 23.099999999999998 23.099999999999998