P.E.I.'s gas prices plunged 5.5 cents Wednesday night, bringing the price between 83.9 and 85 cents per litre — the cheapest it's been since 2009.

The last time the minimum price of regular unleaded gasoline dipped below 84 cents a litre was March 15, 2009, when the prices was between 82.2 and 84.3 cents a litre.

Before that price adjustment, on March 1, 2009, the price was between 81.2 and 83.3.

According to the Island Regulatory and Appeals Commission, the unscheduled drop was due to a decrease in the wholesale price of gas last week.

"Demand for gasoline is relatively low," IRAC said in a written statement. "Against this backdrop, gasoline production has been at an all-time high, resulting in historically high inventory levels."

In contrast, the highest gas prices seen in that time frame were on May 1, 2014, when prices hit between 141.9 and 143.1.

The second highest was on Sept. 1, 2013, at 140.3 to 141.5.

This is the first time the price of premium unleaded gas has dipped below 90 cents a litre in 2016.

But prices could go even lower on Monday, thanks to IRAC's next scheduled price adjustment.