Tel Aviv was ranked the 17th-most expensive city in the world in a recent survey released by Mercer Human Resource Consulting, rising from 24th place in 2006. The most expensive city in the world, for the second consecutive year, is Moscow, according to the survey. London moved up from fifth to second place this year. Rounding out the top five were Seoul, Tokyo and Hong Kong. For the fifth consecutive year, Asuncion, Paraguay ranked as the least expensive city. Tel Aviv was helped by the relative growth of the shekel, making it the most expensive city in the Middle East, ahead of Dubai at 34th, Istanbul at 38th and Abu Dhabi at 45th. Dubai and Abu Dhabi received low rankings based on the relative weakness of the United Arab Emirates's currency, the dirham, which is pegged to the weak US dollar. Istanbul experienced the biggest drop in cost of living among the top 50-ranked cities, falling from 15 in 2006 to 38 this year. Of the top 50 cities, 30 are European, led by London, due to high property rental costs in that city, as well as the strengthening of both the British pound and the Euro. African cities took five spots on the list, led by Douala, Cameroon, in 24th, while eight of the cities are Asian, paced by Seoul, Korea, in third place. Sydney, in 19th place, was the only Australian city to make the top 50. Moscow was helped to first place - along with St. Petersburg in 12th - by significant relative appreciation of the ruble, as well as rising housing prices in Russia. Only two North American cities made the top 50, with New York at 15th and Los Angeles at 42nd, results that were blamed on the weak dollar. No South American cities were included among the top 50, with the continent's most expensive cities, Sao Paulo and Rio de Janeiro, only 62nd and 64th, respectively. The least expensive cities in the rankings, other than Asuncion, are Karachi, Pakistan; Quito, Ecuador and Montevideo, Uruguay, while the least expensive city in Europe is Sofia, Bulgaria, in 108th place. The Mercer survey measures relative costs of housing, food, clothing, household goods and entertainment for expatriates and covers 143 cities on six continents.