condition mean min max ZT0-3 65.922416 65.922416 65.922416 ZT4-7 554.9775549999999 554.9775549999999 554.9775549999999 ZT8-11 1180.1351300000001 1180.1351300000001 1180.1351300000001 ZT12-15 581.428749 581.428749 581.428749 ZT16-19 274.322832 274.322832 274.322832 ZT20-23 137.414484 137.414484 137.414484