condition mean min max ZT0-3 2.652511666666667 2.367445 2.84108 ZT4-7 1.328754 1.328754 1.328754 ZT8-11 1.2431105 1.2431105 1.2431105 ZT12-15 2.7238274999999996 2.6561399999999997 2.791515 ZT16-19 2.89369 2.89369 2.89369 ZT20-23 3.614315 3.614315 3.614315