condition mean min max ZT0-3 15.42955 15.42955 15.42955 ZT4-7 13.22255 13.22255 13.22255 ZT8-11 15.2789 15.2789 15.2789 ZT12-15 15.399899999999999 15.399899999999999 15.399899999999999 ZT16-19 21.3367 21.3367 21.3367 ZT20-23 17.652 17.652 17.652