According to Benjamin Sovacool, nuclear power plants rank first in terms of their economic cost, accounting for 41 percent of all property damage. Oil and hydroelectric follow at around 25 percent each, followed by natural gas at 9 percent and coal at 2 percent. Excluding Chernobyl and the Shimantan Dam, the three other most expensive accidents involved the Exxon Valdez oil spill (Alaska), The Prestige oil spill (Spain), and the Three Mile Island nuclear accident (Pennsylvania). However analysis presented in the international Journal, "Human and Ecological Risk Assessment" found that coal, oil, Liquid petroleum gas and hydro accidents have cost more than nuclear power accidents.