In January, "CNN's Anderson Cooper continued to erode Fox News' lead at 10p," CNN says in its monthly ratings release. "Before Anderson Cooper took over the 10pm time slot Fox News had a 174% advantage in the demo (Aug. 2005). Now that gap is a mere 18% in January. For the fourth month in a row, Anderson Cooper 360 delivered monthly audience gains -- increasing 29% in total viewers at 10pm, while On the Record with Greta Van Susteren declined 7%."

Here is a chart distributed by the network: