Thursday's sixth GOP debate drew 11.1 million viewers to Fox Business Network, making it the least-watched thus far, according to figures released by the Nielsen ratings company. Last month's faceoff, aired on CNN, was seen by 18.2 million. The season's first GOP debate, aired in August on the Fox News Channel, was the most-watched for either party, with 24 million. December's Democratic debate, aired by ABC, was the least-watched overall, with 8 million viewers.