condition mean min max ZT0-3 14.298117 14.298117 14.298117 ZT4-7 14.9872655 14.9872655 14.9872655 ZT8-11 13.913802 13.913802 13.913802 ZT12-15 14.379446000000002 14.379446000000002 14.379446000000002 ZT16-19 13.0253895 13.0253895 13.0253895 ZT20-23 12.6533505 12.6533505 12.6533505