Arena Football League:

On December 19, 2006, ESPN announced the purchase of a minority stake in the AFL. This deal included television rights for the ESPN family of networks. ESPN would televise a minimum of 17 regular season games, most on Monday nights, and nine playoff games, including ArenaBowl XXI on ABC. The deal resulted in added exposure on ESPN's SportsCenter. However, after the original AFL filed for bankruptcy, this arrangement did not carry over to the new AFL, which is a separate legal entity.

Please answer a question about this article. If the question is unanswerable, say "unanswerable". On what date did ESPN buy a minority share of the AFL?
December 19, 2006