what is the tonnage grt of the ship author?
CREATE TABLE table_77988 (
    "Date" text,
    "Ship" text,
    "Type" text,
    "Nationality" text,
    "Tonnage GRT" real
)
SELECT "Tonnage GRT" FROM table_77988 WHERE "Ship" = 'author'
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: what is the tonnage grt of the ship author? ### Input: CREATE TABLE table_77988 (
    "Date" text,
    "Ship" text,
    "Type" text,
    "Nationality" text,
    "Tonnage GRT" real
) ### Response: SELECT "Tonnage GRT" FROM table_77988 WHERE "Ship" = 'author'