Portugal, officially the Portuguese Republic, is a unitary semi-presidential republic. It is located in South-Western Europe, on the Iberian Peninsula, and it is the westernmost country of mainland Europe, being bordered by the Atlantic Ocean to the west and south and by Spain to the north and east. Aside from continental Portugal, the Portuguese Republic holds sovereignty over the Atlantic archipelagos of Azores and Madeira, which are autonomous regions of Portugal. The country is named after its second largest city, Porto, whose Latin name was Portus Cale. Portugal is considered a developed country with an advanced economy and high living standards, listed with the nineteenth-highest quality of life index rating in the world as of 2005. It's one of the world's most globalized and peaceful nations. It is a member of the United Nations, European Union, Eurozone, OECD, NATO, WTO, Schengen Area, and the Community of Portuguese Language Countries. According to OECD, in Portugal, the average household net-adjusted disposable income is $19,366/ year, lower than the OECD average of $23,047/ year, and the average net adjusted disposable income of the top 20% of the population is an estimated $40,277/ year, whereas the bottom 20% earn an estimated $7,079/ year.