condition mean min max ZT0-3 23.621076 23.621076 23.621076 ZT4-7 20.816747499999998 20.816747499999998 20.816747499999998 ZT8-11 31.399026999999997 31.399026999999997 31.399026999999997 ZT12-15 31.0741425 31.0741425 31.0741425 ZT16-19 26.5949265 26.5949265 26.5949265 ZT20-23 19.7817385 19.7817385 19.7817385