condition mean min max ZT0-3 13.536625 12.93285 14.1404 ZT4-7 13.849 13.849 13.849 ZT8-11 16.07555 16.07555 16.07555 ZT12-15 0 0 0 ZT16-19 23.553449999999998 23.553449999999998 23.553449999999998 ZT20-23 15.0111 15.0111 15.0111