condition mean min max ZT0-3 7.750755 6.5762 8.92531 ZT4-7 2.99959 2.99959 2.99959 ZT8-11 1.54862 1.54862 1.54862 ZT12-15 0 0 0 ZT16-19 3.673585 3.673585 3.673585 ZT20-23 3.24208 3.24208 3.24208