The weekly average price of the Organization of Petroleum Exporting Countries (OPEC) kept dropping last week, falling to 103.07 U.S. dollars a barrel, said the Vienna-based cartel said Monday. OPEC oil price has been dropping for four consecutive weeks. During the last four weeks of September, OPEC weekly average oil price fell by 6.4 percent, decreasing from 110.12 U.S. dollars a barrel to 103.07. The weak U.S. economic recovery as well as the debt crisis in Europe remained as the uncertainty factors affecting the global crude oil market last week. While stronger U.S. dollar posed additional pressures on the international oil prices. The figures showed that in the third quarter, the euro exchange rate against the U.S. dollar has declined for the largest range since June 2010. As the U.S. dollar rose about 1 percent, the dollar-denominated oil price thus actually increased, which suppressed the purchase desire of the investors. The investors\' confidence in the rapid economic recovery in Europe reduced greatly due to the drop in the euro exchange rate and the remaining European sovereign debt crisis. As the world\'s largest oil consumer, the economic situation of the United States is not optimistic. Its economic figures showed that its daily oil demand in July kept declining for the fourth month compared with the same period last year. The U.S. personal income in August fell for the first time over the last two years. The U.S. stock market in the third quarter of this year was also considered as the worst quarter since the credit crisis in 2008. During the last day of September, the three major U.S. stock indexes fell by 2 percent. It was reported, in September, OPEC crude oil daily output increased by 100,000 barrels, reaching 30.25 barrels per day, which would be the highest production level since October 2008. Due to the above factors, for a period of time in future, the concerns on the global economic growth would keep increasing without other major incidents happening. Some economists even believe that the concerns about the global economic growth will not only drag oil prices down, but also pose pressures on other commodity prices. Even the gold and copper would also be regarded as risk assets.