ST. PAUL (AP) -- Minnesota Republicans are again accusing Governor Mark Dayton's administration of using shoddy math to show a lower increase in policy costs through the state's health care exchange.

State officials this week said plans on MNsure would rise by 4.5% on average for 2015.

They got the figure by averaging each provider's average increase or decrease.

Senate Minority Leader David Hann says the calculation should have weighed how much of MNsure's market each plan had.

And he said it should have included the largest and cheapest provider, PreferredOne, which is dropping out next year.

Hann says the true increase is more than 15%.

The Commerce Department says it couldn't include rates from the departing plan.

It also says a weighted average wouldn't have been accurate due to PreferredOne's absence.