condition mean min max ZT0-3 2.436625 2.1000199999999998 2.77323 ZT4-7 1.79879 1.79879 1.79879 ZT8-11 7.399295 7.399295 7.399295 ZT12-15 0 0 0 ZT16-19 8.724315 8.724315 8.724315 ZT20-23 4.976175 4.976175 4.976175