user: Question: When Gray Wolves is the team nickname how many institutions are there?
Columns: ['Institution', 'Location', 'Founded', 'Affiliation', 'Enrollment', 'Team Nickname', 'Primary conference']
Types: ['text', 'text', 'real', 'text', 'real', 'text', 'text']
Sample row: ['Aquinas College', 'Grand Rapids, Michigan', 1886.0, 'Private', 2159.0, 'Saints', 'WHAC ( NAIA )']
SQL:

assistant: SELECT COUNT("Institution") FROM "Table" WHERE "Team Nickname" = 'Gray Wolves';