condition mean min max ZT0-3 2.29130763425 2.069480499 2.5131347695 ZT4-7 3.080868058 2.52304369 3.638692426 ZT8-11 3.291125571166667 3.237909379 3.3443417633333334 ZT12-15 2.9752248139999997 2.632142394333333 3.3183072336666664 ZT16-19 3.3121117385 3.157917503 3.466305974 ZT20-23 3.1431861320000003 2.387724904 3.8986473600000005