condition mean min max ZT0-3 416.658017 416.658017 416.658017 ZT4-7 408.5670525 408.5670525 408.5670525 ZT8-11 299.84695350000004 299.84695350000004 299.84695350000004 ZT12-15 234.46968249999998 234.46968249999998 234.46968249999998 ZT16-19 114.493411 114.493411 114.493411 ZT20-23 92.0843505 92.0843505 92.0843505