Oil prices continued to slide on Wednesday, falling on a string of worrying economic news. Markets were peppered with troubling data from September at the start of the week, with each new release compounding fears that cracks in the global economy are growing. Global manufacturing activity declined for the fifth consecutive month in September, the longest period of contraction since 2002. A few automakers posted double-digit percentage declines in car sales – Toyota said its year-on-year sales fell 16.5 percent; Nissan’s sales were…