I searched the Periodical Source Index (available if you're at the Allen County Public Library Genealogy Center or at home via HeritageQuest through your local library) for each state. In thousands, here are the numbers of genealogy articles returned for each state in order (rounded to the nearest thousand):
The Midwest (as defined here) comes in 1, 2, 10, 14, and 20.
Harold Henderson, "Which States Have the Most Genealogy Articles?," Midwestern Microhistory: A Genealogy Blog, posted 9 February 2013 (http://midwesternmicrohistory.blogspot.com : accessed [access date]). [Please feel free to link to the specific post if you prefer.]