condition mean min max ZT0-3 5.662116666666667 4.87636 7.0053149999999995 ZT4-7 4.008495 4.008495 4.008495 ZT8-11 3.9713000000000003 3.9713000000000003 3.9713000000000003 ZT12-15 5.9466325 5.4609000000000005 6.432365 ZT16-19 5.358255 5.358255 5.358255 ZT20-23 5.31405 5.31405 5.31405