U.S. consumer credit increased at an annual rate of 5.9 percent in July, the tenth consecutive monthly growth, offering some relief to a string of weak economic data in recent weeks, the Federal Reserve reported on Thursday.The U.S. central bank said that total borrowing in July rose to 2454.5 billion U.S. dollars from the revised figure of 2442.5 billion dollars in June. The Fed said demand for revolving credit, the category that includes credit cards, dropped 5.2 percent in July after rising 3. 9 percent in June. In July, the borrowing in the non-revolving category which includes auto loans surged at an annual rate of 11.2 percent to 1, 662 billion dollars. Consumer spending, which accounts for about 70 percent of the overall economic activity, remains the major drive for the U.S. economy.