condition mean min max ZT0-3 11.391867 11.391867 11.391867 ZT4-7 13.751307 13.751307 13.751307 ZT8-11 13.9602555 13.9602555 13.9602555 ZT12-15 12.268709999999999 12.268709999999999 12.268709999999999 ZT16-19 12.58585 12.58585 12.58585 ZT20-23 11.8711005 11.8711005 11.8711005