condition mean min max ZT0-3 1.1637721666666667 0.3114565 1.75032 ZT4-7 0.372519 0.372519 0.372519 ZT8-11 1.048315 1.048315 1.048315 ZT12-15 2.3946199999999997 2.102535 2.686705 ZT16-19 1.5613450000000002 1.5613450000000002 1.5613450000000002 ZT20-23 1.738505 1.738505 1.738505