condition mean min max ZT0-3 1.863416 1.404723 2.408085 ZT4-7 1.6227285 1.6227285 1.6227285 ZT8-11 0.6407255000000001 0.6407255000000001 0.6407255000000001 ZT12-15 1.5912675 1.375245 1.80729 ZT16-19 1.0599355 1.0599355 1.0599355 ZT20-23 2.4510300000000003 2.4510300000000003 2.4510300000000003