condition mean min max ZT0-3 3.0227675 2.8784799999999997 3.1670550000000004 ZT4-7 2.857475 2.857475 2.857475 ZT8-11 1.9379549999999999 1.9379549999999999 1.9379549999999999 ZT12-15 0 0 0 ZT16-19 2.9162 2.9162 2.9162 ZT20-23 3.246735 3.246735 3.246735