At about 2 p.m. Saturday, in the District’s generally safe Foggy Bottom area, a man with a gun robbed a business in the 2000 block of Pennsylvania Avenue NW, according to D.C. police.

The Saturday before, in the 700 block of Seventh Street NE, in the H Street corridor, a man threatened to beat an ATM customer. The customer ran, and the robber took the cash that came from the machine, police said. An arrest was made, police said.

A statistical disparity exists in the District between the types of robbery exemplified by the two incidents: those with guns and those without.

As 2018 nears its midpoint, the number of gun robberies has increased from the same time last year, from 310 to 365, or 18 percent.

At the same time the number of robberies reported without a gun has declined from 610 to 507.

By seeming coincidence, the rate of decline in no-gun robberies, 17 percent, is about the same as the increase in gun robberies.

Homicides (71 compared with 48) are the only other category of violent crime to increase so far this year. The total number of violent crimes has declined from 1,960 to 1,835, about 6 percent.