condition mean min max ZT0-3 4.738205 3.4911399999999997 7.14221 ZT4-7 4.42239 4.42239 4.42239 ZT8-11 2.8326849999999997 2.8326849999999997 2.8326849999999997 ZT12-15 3.9185324999999995 2.720965 5.116099999999999 ZT16-19 5.23609 5.23609 5.23609 ZT20-23 7.5246900000000005 7.5246900000000005 7.5246900000000005