https://www.nytimes.com/2018/05/13/business/media/television-advertising.html
National TV ad sales peaked in 2016, when they exceeded $43 billion, according to data from Magna, the ad-buying and media intelligence arm of IPG Mediabrands. Sales fell 2.2 percent last year, and the firm estimates that they will fall at least 2 percent each year through 2022.