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.
The city has had difficulty replacing the lost jobs, and for the past four decades, most people in Lawrence, an estimated 74 percent of whom are Latino, have struggled to get by. Lawrence saw its median household income fall more than 20 percent between 1979 and 2010 to $31,631, the lowest in the state.