Between January 2010 and January 2013, U. employment increase by 4.9 million workers, but the number of unemployed workers declined by only 2.7…

Between January 2010 and January 2013, U.S. employment increase by 4.9 million workers, but the number of unemployed workers declined by only 2.7 million.

How are these numbers consistent with each other?

Why might one expect a reduction in the number of people counted as unemployed to be smaller than the increase in the number of people employed?