What was the issued serial for yellow on blue design issued in 1955?
CREATE TABLE table_49494 (
    "Issued" real,
    "Type" text,
    "Design" text,
    "Serial format" text,
    "Serials issued" text
)
SELECT "Serials issued" FROM table_49494 WHERE "Design" = 'yellow on blue' AND "Issued" = '1955'
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 was the issued serial for yellow on blue design issued in 1955? ### Input: CREATE TABLE table_49494 (
    "Issued" real,
    "Type" text,
    "Design" text,
    "Serial format" text,
    "Serials issued" text
) ### Response: SELECT "Serials issued" FROM table_49494 WHERE "Design" = 'yellow on blue' AND "Issued" = '1955'