CREATE TABLE table_20936 ("Ethnicity" TEXT, "Islam" TEXT, "Christianity" TEXT, "Judaism" TEXT, "Buddhism" TEXT, "Other" TEXT, "Atheism" TEXT, "n/a" TEXT)

When tajik is the ethnicity what is islam?
SELECT "Islam" FROM table_20936 WHERE "Ethnicity" = 'Tajik'
SELECT "Islam" FROM "table_20936" WHERE "Ethnicity" = 'Tajik'