WASHINGTON (AP) — Measures of U.S. inflation barely declined in September, evidence that consumer price increases are grinding lower at a gradual pace. Consumer prices rose 0.4% from August to September, below the previous month’s 0.6% pace. Year-over-year inflation was unchanged last month from a 3.7% rise in August. And underlying inflation declined a bit: So-called core prices, which exclude volatile food and energy costs, climbed 4.1% in September from a year earlier, down from a 4.3% pace in August. That is the smallest such increase in two years. Economists pay particularly close attention to core prices because they provide a good signal of inflation’s likely future path.