user: Question: What shows for the Diameter (mi) when the Gill is G?
Columns: ['Gill', 'Latitude', 'Longitude', 'Diameter (km)', 'Diameter (mi)']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['A', '63.6° S', '72.9° E', '13km', '8mi']
SQL:

assistant: SELECT "Diameter (mi)" FROM "Table" WHERE "Gill" = 'G';