how many countries sampled with year of publication being 2007 and ranking l.a. (2) being 7th
CREATE TABLE table_17378 (
    "Index (Year)" text,
    "Author / Editor / Source" text,
    "Year of publication" text,
    "Countries sampled" real,
    "World Ranking (1)" text,
    "Ranking L.A. (2)" text
)
SELECT COUNT("Countries sampled") FROM table_17378 WHERE "Year of publication" = '2007' AND "Ranking L.A. (2)" = '7th'
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: how many countries sampled with year of publication being 2007 and ranking l.a. (2) being 7th ### Input: CREATE TABLE table_17378 (
    "Index (Year)" text,
    "Author / Editor / Source" text,
    "Year of publication" text,
    "Countries sampled" real,
    "World Ranking (1)" text,
    "Ranking L.A. (2)" text
) ### Response: SELECT COUNT("Countries sampled") FROM table_17378 WHERE "Year of publication" = '2007' AND "Ranking L.A. (2)" = '7th'