user: Question: In what years was the conference record 18-15?
Columns: ['Coach', 'Years', 'Record', 'Conference Record', 'Overall Win Percentage']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['James C. Elsom', '1898–1904', '25-14', '–', '64%']
SQL:

assistant: SELECT "Years" FROM "Table" WHERE "Conference Record" = '18-15';