in-depth investigative reporting to the degree carried out by 60 Minutes. Eventually, during the summers of 1973 through 1975, CBS did allow the program back onto the prime time schedule proper, on Fridays in 1973 and Sundays the two years thereafter, as a replacement for programs aired during the regular television season. It was only when the FCC returned an hour to the networks on Sundays (for news or family programming), which had been taken away from them four years earlier, in a 1975 amendment to the Access Rule, that CBS finally found a viable permanent timeslot for 60 Minutes. When the family-oriented drama Three for the Road ended after a 12-week run in the fall, the news magazine took its place at 7:00 p.m. Eastern Time (6:00 p.m. Central) on December 7, 1975. It has aired at that time since for 47 years , making it not only the longest-running prime time program currently in production, but also the television program (excluding daily programs such as evening newscasts or morning news-talk shows) broadcasting for the longest length of time at a single time period each week in U.S. television history. This move, and the addition of then-White House correspondent Dan Rather to the reporting team, made the program into a strong ratings hit and, eventually, a general cultural phenomenon. This was no less than a stunning reversal of the historically poor ratings performances of documentary programs on network television. By 1976, 60 Minutes became the top-rated program on Sunday nights in the U.S. By 1979, it had achieved the #1 spot among all television programs in the Nielsen ratings, unheard of before for a news broadcast in prime time. This success translated into great profits for CBS; advertising rates increased from $17,000 per 30-second spot in 1975 to $175,000 in 1982. The program sometimes does not start until after 7:00 p.m. Eastern, due largely to CBS Sports live sporting events. At the conclusion of an NFL game, 60 Minutes will air in its entirety and delay all subsequent programs. However, in the Pacific time zone, 60 Minutes is always able to start at its scheduled time as live sports coverage ends earlier in the afternoon. The program's success has also led CBS Sports to schedule events (such as the final round of the Masters Tournament and the second round and regional final games of the NCAA men's basketball tournament)