user: Question: What is the total number of Tonnage, when Date is "25 june 1943"?
Columns: ['Date', 'Ship', 'Nationality', 'Tonnage', 'Fate']
Types: ['text', 'text', 'text', 'real', 'text']
Sample row: ['9 September 1941', 'Empire Springbuck', 'UK', 5591.0, 'Sunk']
SQL:

assistant: SELECT SUM("Tonnage") FROM "Table" WHERE "Date" = '25 june 1943';