How much money do you think you have saved in recent weeks as gas prices started to plummet? More than $100: Less than $100?

Well, you will continue to save as average retail gasoline prices in Billings have fallen 8.9 cents per gallon in the past week, averaging $1.80 per gallon on Sunday, according to GasBuddy's daily survey of 81 gas outlets in Billings. This compares with the national average that has fallen 6.5 cents per gallon in the last week to $1.82 per gallon, according to gasoline price website GasBuddy.com.

Areas nearby Billings and their current gas price climate:

  • Montana- $1.83 per gallon, down 6.9 cents per gallon from last week's $1.90 per gallon
  • Idaho- $2.03 per gallon, down 4.3 cents per gallon from last week's $2.08 per gallon
  • Wyoming- $1.78 per gallon, down 7.5 cents per gallon from last week's $1.85 per gallon.

Including the change in gas prices in Billings during the past week, prices Sunday were 9.0 cents per gallon lower than the same day one year ago and are 18.9 cents per gallon lower than a month ago. The national average has decreased 17.5 cents per gallon during the last month and stands 20.0 cents per gallon lower than this day one year ago.

Crude oil futures have lost 18 percent of value since the end of 2015 and have cleared the way for the retail gasoline price decline, according to Will Speer, a GasBuddy senior petroleum analyst..

Ample supply has been attributed as the cause of prices falling at the pump," Speer said in a prepared statement. "Gasoline inventories sitting at 245 million barrels are the highest the U.S. has seen since March 1990."