user: Question: What year did the team make conference semifinals?
Columns: ['Year', 'Division', 'League', 'Regular Season', 'Playoffs', 'U.S. Open Cup', 'Avg. Attendance']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1999.0, '2', 'USL A-League', '4th, Northeast', 'Conference Semifinals', 'Did not qualify', '4,559']
SQL:

assistant: SELECT "Year" FROM "Table" WHERE "Playoffs" = 'conference semifinals';