condition mean min max ZT0-3 4.756945 4.47978 5.03411 ZT4-7 5.44007 5.44007 5.44007 ZT8-11 3.0564 3.0564 3.0564 ZT12-15 0 0 0 ZT16-19 2.5015099999999997 2.5015099999999997 2.5015099999999997 ZT20-23 4.485144999999999 4.485144999999999 4.485144999999999