Which population has a GDP (nominal) of $6.4 billion?
CREATE TABLE table_name_63 (
    population VARCHAR,
    gdp__nominal_ VARCHAR
)
SELECT population FROM table_name_63 WHERE gdp__nominal_ = "$6.4 billion"
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: Which population has a GDP (nominal) of $6.4 billion? ### Input: CREATE TABLE table_name_63 (
    population VARCHAR,
    gdp__nominal_ VARCHAR
) ### Response: SELECT population FROM table_name_63 WHERE gdp__nominal_ = "$6.4 billion"