condition mean min max ZT0-3 370.241288 370.241288 370.241288 ZT4-7 504.0713395 504.0713395 504.0713395 ZT8-11 546.3158105 546.3158105 546.3158105 ZT12-15 572.5710965000001 572.5710965000001 572.5710965000001 ZT16-19 541.2599305 541.2599305 541.2599305 ZT20-23 507.68888949999996 507.68888949999996 507.68888949999996