condition mean min max ZT0-3 3.842945 2.92223 5.078455 ZT4-7 3.0164 3.0164 3.0164 ZT8-11 3.8817700000000004 3.8817700000000004 3.8817700000000004 ZT12-15 10.1049475 9.610395 10.599499999999999 ZT16-19 8.30272 8.30272 8.30272 ZT20-23 8.051235 8.051235 8.051235