The series has a large ensemble cast. Over ten seasons, 33 people have appeared in the opening credits as leading cast members. The show features a sprawling supporting cast, with 54 people credited as "additional cast" or "featured" in the show's end credits. These secondary cast members appear in green screen confessional segments and (for the most part) have the same amount of screen time and storyline focus as the show's main cast members. Over the years, several supporting cast members have been upgraded to lead.