condition mean min max ZT0-3 26.380598 26.380598 26.380598 ZT4-7 28.1706455 28.1706455 28.1706455 ZT8-11 31.442368000000002 31.442368000000002 31.442368000000002 ZT12-15 22.6797885 22.6797885 22.6797885 ZT16-19 29.826081000000002 29.826081000000002 29.826081000000002 ZT20-23 31.9990155 31.9990155 31.9990155