Fuel oil prices rose another 2 cents over the past week, reaching a statewide average Monday of $2.38 per gallon for No. 2.

Kerosene rose by 2 cents as well, while propane shot up 6 cents per gallon, according to figures provided by the state Office of Energy Independence and Security.

The OEIS surveys heating fuel dealers weekly from October through March.

The increases mean No. 2 is selling for 48 cents more than it did a year ago, and kerosene costs people 60 cents more per gallon today than it did on this date in 2005. Propane is up 21 cents on the year.

A 50-cent annual increase in the cost of heating oil – the fuel that warms nearly 80 percent of Maine’s single family homes – represents a $500 jump in costs if the home uses 1,000 gallons annually.

The OEIS said the week’s oil price increase comes at a time when national distillate inventories are up by more than 10 million barrels over last year; the New England heating oil inventory was up more than 2,000 barrels.

World oil prices shot up over the week, with crude topping $68 per barrel on Monday, a figure that’s within pennies of record levels. The climb in crude prices is reflected in heating fuels as well as at gasoline pumps.

Fueling the price increases are several global factors.

One is a looming standoff between Western nations and Iran over Iran’s plans to develop nuclear power. The Western nations, including the United States, fear Iran is planning to direct nuclear fuel to weapons development. Iran says its nuclear ambitions are peaceful, but cautioned that any actions against it could prompt Iran to withhold oil from the world market. Iran is the No. 2 producer of oil behind Saudi Arabia.

Another issue contributing to rising oil prices is localized political strife in Nigeria. There, protesters have taken some Royal Dutch Shell oil workers hostage and led some producers to temporarily limit oil production.