condition mean min max ZT0-3 21.822129 21.822129 21.822129 ZT4-7 15.894419 15.894419 15.894419 ZT8-11 16.343167 16.343167 16.343167 ZT12-15 13.776285999999999 13.776285999999999 13.776285999999999 ZT16-19 15.4613795 15.4613795 15.4613795 ZT20-23 17.399528 17.399528 17.399528