Some risk communication situations require helping people to visualize just how rare very rare events are. A common example occurs in prenatal genetic testing. If a couple has no other risk factors, the baseline risk of genetic diseases such as Down Syndrome is often much smaller than even 1 in 1000 (0.1%). Visually showing this ratio is challenging.
This multi-bar graphic uses reference bars at 100%, 50%, 10%, and 1% to make the smallness of the 0.08% risk level much clearer.
Please note the European convention of writing 0,08% rather than the American convention of 0.08%. The graphic was tested in this way (in error), but should be corrected before using it with American audiences.