condition mean min max ZT0-3 1.345627 1.345627 1.345627 ZT4-7 1.1107585 1.1107585 1.1107585 ZT8-11 0.926455 0.926455 0.926455 ZT12-15 1.084789 1.084789 1.084789 ZT16-19 2.58765 2.58765 2.58765 ZT20-23 1.727265 1.727265 1.727265