condition mean min max ZT0-3 25.477481 25.477481 25.477481 ZT4-7 22.955557499999998 22.955557499999998 22.955557499999998 ZT8-11 26.1834645 26.1834645 26.1834645 ZT12-15 20.8199945 20.8199945 20.8199945 ZT16-19 21.8488205 21.8488205 21.8488205 ZT20-23 25.6014305 25.6014305 25.6014305