Looks like 6 years. Pertaining to Sinclair Broadcast Group. AP article here: https://archive.ph/Ug5GB

The anchors give no specific examples. Sinclair, whose corporate leadership leans right, uses terminology familiar to Trump and his criticisms of “fake news.” In the message, the anchors say they “work very hard to seek the truth and strive to be fair, balanced and factual.”
Timothy Burke, a video editor at Deadspin, said he read a CNN story last month about the script being sent to local stations and contacted a media monitoring service to collect examples of the statement being read on the air. After receiving more than 50, he fashioned them into a video that shows anchors reading different portions of the text, either simultaneously or one after the other.