user: Question: In what year was Martin Sheen nominated?
Columns: ['Year', 'Category', 'President', 'Nominee', 'Film or Television Series or Miniseries']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [1964.0, 'Best Actor – Motion Picture Drama', 'Jordan Lyman', 'Fredric March', 'Seven Days in May']
SQL:

assistant: SELECT "Year" FROM "Table" WHERE "Nominee" = 'Martin Sheen';