AMC's midseason premiere of The Walking Dead in the U.S. returned with its largest audience ever in series history, delivering 12.3 million viewers at the 9/8c premiere. The previous record was 10.9 million viewers from the Season 3 premiere on October 14, 2012. According to the network, the episode is also the strongest telecast for a series in basic cable history for adults 18-49 with 7.7 million. These results have surpassed the hit series' previous record with an increase of 6% (A18-49) over … [Read more...] about AMC’s “The Walking Dead” achieves its biggest ratings