"U.S. viewers (million)" refers to the number of Americans in millions who watched the episode as it was aired.

"U.S. viewers in millions" refers to the number of Americans in millions who watched the episodes live or recorded them and watched them within seven days of broadcast.

In the following table, "U.S. viewers in millions" refers to the number of Americans who viewed the episode on the day of original broadcast.

"U.S. viewers in millions" refers to how many Americans watched the episode live or on the day of broadcast.

"U.S. viewers (million)" refers to the number of Americans who viewed the episode on the night of broadcast.

"U.S. viewers in millions" refers to the number of Americans in millions who watched the episodes live.