user: Question: how many number is located at registration F-BVFF?
Columns: ['Number', 'Registration', 'First flew', 'Last flew', 'Flying hours', 'Location']
Types: ['real', 'text', 'text', 'text', 'real', 'text']
Sample row: [1.0, 'F-WTSS', '2 March 1969', '19 October 1973', 812.0, 'The Museum of Air and Space , Le Bourget, France']
SQL:

assistant: SELECT COUNT("Number") FROM "Table" WHERE "Registration" = 'F-BVFF';