U.S. average retail pump prices for both diesel and gasoline continued to decline this week, according to data tracked by the Energy Information Administration (EIA), and are now lower than during the same time period last year.

Diesel dropped 2.5 cents this week to $3.869 per gallon, the agency reported, which is 3.4 cents cheaper compared to the same week in 2013.

EIA added that diesel prices declined in every region of the country this week, with only four areas reporting prices above the $4 per gallon mark: New England at $4.025 per gallon; the Central Atlantic at $4.014, which also recorded the biggest one-week price drop of 3.7 cents per gallon; California at $4.096; and the West Coast at $4.026, though that drops to $3.942 when California’s prices are removed from the mix.

Gasoline prices fell 4.2 cents this week to $3.593 per gallon, which is 8.9 cents lower per gallon compared to the same week in 2013, the agency noted.

All regions reported declines in gasoline prices, with the Gulf Coast recording the largest at 4.6 cents down to $3.394 per gallon, which is also the cheapest average gasoline price in the nation, EIA pointed out.

The Lower Atlantic posted the second biggest one-week decline and also the second cheapest price mark for gasoline: a 4.5-cent drop to $3.489. The Midwest and Central Atlantic tied for the third largest week-over-week decline of 4.2 cents, the agency noted, with prices per gallon in those regions reaching $3.497 and $3.665, respectively.

In other news, EIA noted that rising domestic crude oil production is affecting the U.S. trade deficit.

Since the mid-1970s, the agency said the U.S. has run a deficit in merchandise trade as payments for imports exceeded receipts for exports – reaching a maximum of $883 billion in the second quarter of 2008.

But because of the Great Recession, dramatic declines of imports in excess of exports during the fourth quarter of 2008 and the first quarter of 2009 reduced the nation’s trade deficit by 49% – down to $449 billion by the second quarter of 2009, the lowest quarterly deficit mark since early 2002.

However, since 2009 the U.S. trade deficit widened, reaching $686 billion by the fourth quarter of 2013, with much of the difference from the 2008 level – some $131 billion worth – attributable to a $158 billion increase in net exports of crude oil and petroleum products.

Crude oil and petroleum products play a significant role in the balance of U.S. trade accounts, EIA explained, and the value of petroleum trade is sensitive to both changes in price and volume. Historically, the U.S. imported more petroleum and petroleum products than it has exported. And while trade in petroleum and petroleum products contributes to the overall U.S. goods deficit, that deficit would exist even if the U.S. did not import oil, the agency stressed.

EIA added that, while there have been recent increases in crude oil exports, nearly all of the petroleum exports through 2013 were of refined petroleum products such as gasoline.