Article: The top ten (eleven in season ten) toured at the end of every season. In the season twelve tour a semi-finalist who won a sing-off was also added to the tour. Kellogg's Pop-Tarts was the sponsor for the first seven seasons, and Guitar Hero was added for the season seven tour. M&M's Pretzel Chocolate Candies was a sponsor of the season nine tour. The season five tour was the most successful tour with gross of over $35 million.

Question: Which was the most successful tour?
season five