condition mean min max ZT0-3 8.697468333333333 4.5010449999999995 11.4624 ZT4-7 8.30005 8.30005 8.30005 ZT8-11 15.34065 15.34065 15.34065 ZT12-15 12.581875 11.82035 13.343399999999999 ZT16-19 12.5001 12.5001 12.5001 ZT20-23 15.49745 15.49745 15.49745