user: Question: What years did the Nashville Metros have USISL Indoor League?
Columns: ['Year', 'Division', 'League', 'Regular Season', 'Playoffs']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['1990/91', 'N/A', 'SISL Indoor', '9th, Southeast', 'Did not qualify']
SQL:

assistant: SELECT "Year" FROM "Table" WHERE "League" = 'USISL Indoor';