Only four states are posting average gas prices below $2 per gallon.

The national average price of gasoline has climbed for 14 straight days to $2.21 per gallon, according to a report by AAA. The uptick follows the OPEC oil production agreement set on Nov. 30.

The national average 20 cents higher compared to this time last year.

AAA noted that at the end of November, OPEC agreed to cut output by 1.2 million barrels per day beginning January 2017 and markets have been reacting to the news, with crude oil prices hitting an 18-month high. Retail prices, meanwhile have continued to increased. The effectiveness of the deal and continued market impacts remains to be seen and it hinges on all countries implementing the agreed to production levels.

According to the report, now only four states are posting average gas prices below $2. They are Oklahoma ($1.96), Missouri ($1.97), Arkansas ($1.98) and Texas ($1.99). Michigan (+23 cents), Indiana (+22 cents), Ohio (+21 cents), Illinois (+15 cents), Kentucky (+13 cents) and Delaware (+12 cents) have seen the highest uptick in gas prices since last month.