condition mean min max ZT0-3 665.1451666666667 591.663 735.5515 ZT4-7 635.0350000000001 635.0350000000001 635.0350000000001 ZT8-11 497.24350000000004 497.24350000000004 497.24350000000004 ZT12-15 237.01375000000002 229.0885 244.939 ZT16-19 290.46900000000005 290.46900000000005 290.46900000000005 ZT20-23 428.5 428.5 428.5