Denver voters are turning in their runoff ballots at a rate that exceeds every mayoral election in the city since at least 2011. In an election that will name either Kelly Brough or Mike Johnston Denver’s first new mayor in a dozen years and decide the direction of the next City Council with three seats still up for grabs, officials are being careful not to read too much into what those strong early returns might signal. The priority on Tuesday night will be making sure all ballots turned in on Election Day are scanned as quickly as possible to let voters know they have been received, Denver Elections Division spokeswoman Lucille Wenegieme said.