CREATE TABLE table_65497 ("Index" TEXT, "Score" TEXT, "PALOP rank" TEXT, "CPLP rank" TEXT, "n Africa rank" TEXT, "World rank" TEXT, "Year" FLOAT)

What year had a score of 0.586?
SELECT COUNT("Year") FROM table_65497 WHERE "Score" = '0.586'
SELECT COUNT("Year") FROM "table_65497" WHERE "Score" = '0.586'