condition mean min max ZT0-3 4.695153333333333 4.0721799999999995 5.50453 ZT4-7 6.4478100000000005 6.4478100000000005 6.4478100000000005 ZT8-11 6.3324 6.3324 6.3324 ZT12-15 8.287185000000001 7.258065 9.316305 ZT16-19 5.2416149999999995 5.2416149999999995 5.2416149999999995 ZT20-23 5.56602 5.56602 5.56602