condition mean min max ZT0-3 2.6865550000000002 2.6865550000000002 2.6865550000000002 ZT4-7 1.786515 1.786515 1.786515 ZT8-11 2.9120850000000003 2.9120850000000003 2.9120850000000003 ZT12-15 2.671425 2.671425 2.671425 ZT16-19 4.03763 4.03763 4.03763 ZT20-23 3.332655 3.332655 3.332655