condition mean min max ZT0-3 8.274094999999999 8.274094999999999 8.274094999999999 ZT4-7 7.39184 7.39184 7.39184 ZT8-11 8.17128 8.17128 8.17128 ZT12-15 6.455875000000001 6.455875000000001 6.455875000000001 ZT16-19 7.8509150000000005 7.8509150000000005 7.8509150000000005 ZT20-23 7.48388 7.48388 7.48388