condition mean min max ZT0-3 6.26262 6.26262 6.26262 ZT4-7 1.678915 1.678915 1.678915 ZT8-11 2.738725 2.738725 2.738725 ZT12-15 5.652215 5.652215 5.652215 ZT16-19 8.502845 8.502845 8.502845 ZT20-23 5.959695 5.959695 5.959695