CREATE TABLE table_17378 ("Index  ( Year ) " TEXT, "Author / Editor / Source" TEXT, "Year of publication" TEXT, "Countries sampled" FLOAT, "World Ranking  ( 1 ) " TEXT, "Ranking L.A.  ( 2 ) " TEXT)

how many countries sampled with year of publication being 2007 and ranking l.a. (2) being 7th
SELECT COUNT("Countries sampled") FROM table_17378 WHERE "Year of publication" = '2007' AND "Ranking L.A. (2)" = '7th'
SELECT COUNT("Countries sampled") FROM "table_17378" WHERE "Ranking L.A. (2)" = '7th' AND "Year of publication" = '2007'