In my book, that is a 20% increase, not a 16.67% increase. It would be more
conventional to divide by the *original* value, A2, rather than by B2.
Also, it is often more sensible not to multiply by 100 but merely to format
as percentage. That way, the percentage can be used in subsequent
calculations without having to divide by 100.
Hence, =(B2-A2)/A2 or =B2/A2-1