user: Question: What season has a number less than 90, Mitte as the league and SpVgg Ruhmannsfelden as the team?
Columns: ['Record', 'Team', 'Season', 'League', 'Number']
Types: ['text', 'text', 'text', 'text', 'real']
Sample row: ['Most wins', 'SpVgg Weiden', '1987-88', 'Mitte', 30.0]
SQL:

assistant: SELECT "Season" FROM "Table" WHERE "Number" < 90.0 AND "League" = 'Mitte' AND "Team" = 'SpVgg Ruhmannsfelden';