condition mean min max ZT0-3 11.257275 10.92775 11.5868 ZT4-7 16.85115 16.85115 16.85115 ZT8-11 10.089500000000001 10.089500000000001 10.089500000000001 ZT12-15 0 0 0 ZT16-19 12.65075 12.65075 12.65075 ZT20-23 19.182949999999998 19.182949999999998 19.182949999999998