condition mean min max ZT0-3 2.551865 2.551865 2.551865 ZT4-7 1.68227 1.68227 1.68227 ZT8-11 11.249600000000001 11.249600000000001 11.249600000000001 ZT12-15 14.72495 14.72495 14.72495 ZT16-19 11.94305 11.94305 11.94305 ZT20-23 5.23274 5.23274 5.23274