In fresh signs that the global economy remains shaky â¿¿ and challenging for U.S. exporters â¿¿ leaders of central banks in Japan and the European Union signaled Thursday they were taking or preparing to take more aggressive steps to stimulate economic growth in their regions.The Bank of Japan said it would pump money into the Japanese financial system to help pull the world's third-largest economy out of its prolonged slump. And the head of the European Central Bank, Mario Draghi, said the bank was considering a range of fresh options to stimulate growth. The outlook was a bit brighter in the U.S. Obama's starting point was 2009 exports of $1.57 trillion. Since then, they've climbed to a record $2.19 trillion in 2012 â¿¿ about 48 percent toward his goal of some $3.14 trillion a year by the start of 2015. But 2012 exports, while a record, grew just 5.5 percent from those in 2011, down from a 15.9 percent surge from 2010 to 2011. The rate would have to pick up sharply again this year and next to meet Obama's target. "Some of the headwinds we faced last year have started to improve," said Chad Moutay, chief economist for the National Association of Manufacturers. "And I think energy is a game-changer. We definitely have increased the competitiveness of U.S. manufacturing." U.S. manufacturers posted a fourth consecutive month of expansion in March. While the rate was a bit below February's gain, the overall trend is still up. Some critics argue that Obama set the bar artificially low by using recessionary 2009 numbers as his starting point. Alan Tonelson, an official with the U.S. Business and Industry Council, said Obama also "has the wrong goal" by focusing on exports and not the other part of the trade equation: still-huge import levels and resulting trade deficits.