U.S. energy firms added oil and natural gas rigs this week, boosting the oil count for the fourth month in a row as producers return to the wellpad with crude prices mostly trading over $40 a barrel since mid June.

The oil and gas rig count, an early indicator of future output, rose 10 to 320 in the week to Nov. 25, energy services firm Baker Hughes Co. said in its closely followed report on Nov. 25.

This was the 10th weekly increase in 11 weeks.

“There was a single week decline in oil drilling activity (last week) going against the recent trend in higher drilling activity. This could just be weekly noise or possibly lower drilling ahead of the Thanksgiving holiday which is not usual,” James Williams at WTRG Economics in Arkansas said.

Baker Hughes released the rig count a couple days ahead of usual due to the U.S. Thanksgiving Day holiday on Thursday.

This week’s count was 482 rigs, or 60%, below this time last year.

That boosted the total rig count by 24 in November, its fourth monthly rise in a row for the first time since December 2018.

The number of operating rigs has surged since August, when it hit a record low of 244, according to Baker Hughes data going back to 1940.

U.S. oil rigs rose 10 to 241 this week, their highest since May, while as rigs rose by one to 77, their highest since June, according to Baker Hughes data. The miscellaneous rig count fell by one.

U.S. crude futures were trading around $46 a barrel on Nov. 25, up about 145% over the past seven months, on hopes that effective coronavirus vaccines will spur the return of oil demand.