user: Question: What's the year when 1851 had 634?
Columns: ['Year', '1851', '1861', '1871', '1881']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Year', '1851', '1861', '1871', '1881']
SQL:

assistant: SELECT "Year" FROM "Table" WHERE "1851" = '634';