NEW YORK — The U.S. rate for gun deaths has increased for the second straight year, following 15 years of no real change, a government report shows.Roughly two-thirds of gun deaths are suicides and those have been increasing for about 10 years. Until recently, that has been offset by a decline in people shot dead by others. But there's been a recent upswing in those gun-related homicides, too, some experts said.Overall, the firearm death rate rose to 12 deaths per 100,000 people last year, up from 11 in 2015, according to the report released Friday by the Centers for Disease Control and Prevention.