user: Question: Which currency has a central rate of 0.702804?
Columns: ['Currency', 'Code', 'Entry ERM II', 'Central rate', 'Official target date']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Bulgarian lev', 'BGN', '—', '1.95583', '—']
SQL:

assistant: SELECT "Currency" FROM "Table" WHERE "Central rate" = '0.702804';