Power production in the continental United States totaled 77,184 gigawatt hours (GWh) in the week ended June 15, down 9.2% from the same week a year ago, the Edison Electric Institute (EEI) said in a report on Wednesday.

The week's output was about 2% lower than the 78,930 GWh produced in the preceding seven-day period, according to EEI data.

Year-on-year output fell in seven of the nine US geographical regions tracked by the electric power trade group.

The West Central region registered the biggest year-on-year percentage decline at 16.5%, followed by the Central Industrial region at 15.6%.

For the past 52 weeks, US power production totaled 4,070,134 GWh, up 0.3% from the prior 52-week period, the EEI added.