Eleven states are posting pump prices below $2 per gallon, and prices are expected to continue to decline through the end of the year.

The national average price for gas has fallen to $2.16 as of Nov. 16, having decreased for 10 straight days, according to a report by AAA.

AAA noted that the average U.S. price for gas could fall below $2 per gallon by Dec. 25 for the first time since 2009.

Refinery production in the Midwest appears to be recovering, which should help prices in the region to decline. Gas demand usually dips in November, AAA pointed out, and now that fall refinery maintenance is drawing to a close, drivers should see gas prices move lower through the end of the year “barring any unanticipated outages or supply disruptions.”

Eleven states are posting averages below $2 per gallon. South Carolina continues to boast the lowest price per gallon for gas in the country at $1.91. Hawaii, at $2.86, continues to have the highest pump prices, followed by California ($2.80), Nevada ($2.67), Washington ($2.52) and Oregon ($2.41).