condition mean min max ZT0-3 2.6493849999999997 2.252145 3.0466249999999997 ZT4-7 1.68064 1.68064 1.68064 ZT8-11 2.027845 2.027845 2.027845 ZT12-15 0 0 0 ZT16-19 2.29556 2.29556 2.29556 ZT20-23 2.4095250000000004 2.4095250000000004 2.4095250000000004