CREATE TABLE table_39517 ("Source" TEXT, "Date" TEXT, "DeSUS" TEXT, "Zares" TEXT, "NLPD" TEXT)

What is the percentage for Zares on May 21 22?
SELECT "Zares" FROM table_39517 WHERE "Date" = 'may 21–22'
SELECT "Zares" FROM "table_39517" WHERE "Date" = 'may 21–22'