condition mean min max ZT0-3 31.380525704166665 28.891076373333334 33.869975034999996 ZT4-7 14.544578960166668 10.655406967000001 18.433750953333334 ZT8-11 6.038351363 4.725249412 7.3514533140000005 ZT12-15 7.4049500901666665 6.867585362 7.942314818333333 ZT16-19 7.522305152833334 7.293912338666667 7.750697967000001 ZT20-23 8.555397354333333 7.544004122666667 9.566790586