During what season did American Idol become the highest rated show across all demographics? 
The growth continued into the next season, starting with a season premiere of 26.5 million. The season attracted an average of 21.7 million viewers, and was placed second overall amongst the 18–49 age group. The finale night when Ruben Studdard won over Clay Aiken was also the highest-rated ever American Idol episode at 38.1 million for the final hour. By season three, the show had become the top show in the 18–49 demographic a position it has held for all subsequent years up to and including season ten, and its competition stages ranked first in the nationwide overall ratings. By season four, American Idol had become the most watched series amongst all viewers on American TV for the first time, with an average viewership of 26.8 million. The show reached its peak in season five with numbers averaging 30.6 million per episode, and season five remains the highest-rated season of the series.