This was a product of the Mutual Broadcasting System. It was carried on their satellite system as well as distributed to "offline" stations by disc. Information here provided by Wikipedia, and as best I remember, is accurate.....
In 1981, he created The Dick Clark National Music Survey for the Mutual Broadcasting System. The program counted down the Top 30 contemporary hits of the week in direct competition with American Top 40. Clark left Mutual in 1986, and Charlie Tuna took over the National Music Survey. Clark then launched his own radio syndication group; the United Stations Radio Network, or Unistar, and took over the countdown program, "Countdown America". It ran until 1994, when Clark sold Unistar to Westwood One Radio. The following year, Clark started over, building a new version of the USRN and a new countdown show: "The U.S. Music Survey". He served as its host until his 2004 stroke.
Later . . . .