When was the first elected when the party was republican and the candidate were robert h. michel (r) 66.1% rosa lee fox (d) 33.9%?
CREATE TABLE table_18378 (
    "District" text,
    "Incumbent" text,
    "Party" text,
    "First elected" real,
    "Result" text,
    "Candidates" text
)
SELECT MIN("First elected") FROM table_18378 WHERE "Party" = 'Republican' AND "Candidates" = 'Robert H. Michel (R) 66.1% Rosa Lee Fox (D) 33.9%'
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: When was the first elected when the party was republican and the candidate were robert h. michel (r) 66.1% rosa lee fox (d) 33.9%? ### Input: CREATE TABLE table_18378 (
    "District" text,
    "Incumbent" text,
    "Party" text,
    "First elected" real,
    "Result" text,
    "Candidates" text
) ### Response: SELECT MIN("First elected") FROM table_18378 WHERE "Party" = 'Republican' AND "Candidates" = 'Robert H. Michel (R) 66.1% Rosa Lee Fox (D) 33.9%'