condition mean min max ZT0-3 27.873559 27.873559 27.873559 ZT4-7 30.127471 30.127471 30.127471 ZT8-11 31.998011 31.998011 31.998011 ZT12-15 25.796208 25.796208 25.796208 ZT16-19 22.133905 22.133905 22.133905 ZT20-23 24.2714405 24.2714405 24.2714405