user: Question: At a longitude of 109.9E, how many features were found?
Columns: ['Name', 'Latitude', 'Longitude', 'Diameter (km)', 'Year named', 'Name origin']
Types: ['text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['Fornax Rupes', '30.3N', '201.1E', '729.0', 1985.0, 'Roman goddess of hearth and baking of bread.']
SQL:

assistant: SELECT COUNT("Diameter (km)") FROM "Table" WHERE "Longitude" = '109.9E';