Emphasis. The colon can be used to emphasize a phrase or single word at the end of a sentence. An em dash can be used for the same purpose. In the second example below, an em dash is more common than a colon, though the use of a colon is nevertheless correct.
Lawrenceville, GA Income and Careers. As of 2010-2014, the per capita income of Lawrenceville is $19,178, which is lower than the state average of $25,427 and is lower than the national average of $28,555. Lawrenceville median household income is $42,459, which has shrunk by 1.94% since 2000.
Monticello median household income is $22,897 in 2008-2012 and has grown by 1.00% since 2000. The income growth rate is much lower than the state average rate of 32.93% and is much lower than the national average rate of 26.32%.