Average retail pump prices for diesel and gasoline dropped slightly this week, according to data tracked by the Energy Information Administration – falling 1.1 cents and 2.9 cents per gallon, respectively – with the agency adding that there’s been a significant jump in domestic crude oil usage by East Coast refineries this year.

The EIA said that the average retail pump price for diesel in the U.S. fell 1.1 cents to $3.964 per gallon this week, though that’s 11.9 cents per gallon higher compared to the same week in 2013. The agency added that prices dropped in all regions of the country, with New England witnessing the biggest one-week decline of 2.7 cents per gallon.

Currently, diesel exceeds the $4 per gallon mark in five regions of the country: the East Coast ($4.055 per gallon); New England ($4.181); the Central Atlantic ($4.176); the West Coast ($4.046); and California ($4.132).

Average retail pump prices for gasoline dropped 2.9 cents to $3.684 per gallon this week – though that’s 14.6 cents higher compared to the same week in 2013 – with prices falling in every region of the U.S. except for the Rocky Mountains (up 1.9 cents to $3.501 per gallon) and the West Coast sans California (up 4/10ths of a penny to $3.765).

With California included in the mix, the price for gasoline exceeded the $4 per gallon mark on the West Coast at $4.055 per gallon, though that represents a one-week decline of 1.8 cents per gallon. By contrast, the Midwest experienced the biggest one-week decline in gasoline prices of 6.7 cents to $3.595 per gallon.

In other petroleum-related data mining efforts, the EIA noted that receipts of domestic crude oil at East Coast (PADD 1) refineries in January were approximately equal to receipts of foreign crude oil – reflecting a very significant change, as in January 2013, domestic crude oil was only 18% of total PADD 1 crude receipts, with domestic crude accounting for just 5% of PADD 1 receipts in January 2012.

The agency believes rising U.S. crude oil production in the Bakken formation in North Dakota combined with the expansion of crude-by-rail infrastructure, which has facilitated movement of Bakken crude to PADD 1, contributed to this supply increase for East Coast refineries – adding that Bakken crude oil is a “good fit” for most East Coast refineries, which generally favor a “light sweet” type of crude oil.