condition mean min max ZT0-3 18.503261 18.503261 18.503261 ZT4-7 12.7879665 12.7879665 12.7879665 ZT8-11 14.093467 14.093467 14.093467 ZT12-15 13.83113 13.83113 13.83113 ZT16-19 15.8081185 15.8081185 15.8081185 ZT20-23 14.789639999999999 14.789639999999999 14.789639999999999