CREATE TABLE table_51947 ("Rank  (  WJC  ) " FLOAT, "Rank  ( ARDA ) " FLOAT, "Metro area" TEXT, "Number of Jews  ( WJC ) " FLOAT, "Number of Jews  ( ASARB ) " FLOAT)

What was the number of WJC Jews with a WJC rank of 6?
SELECT "Number of Jews (WJC)" FROM table_51947 WHERE "Rank ( WJC )" = '6'
SELECT "Number of Jews (WJC)" FROM "table_51947" WHERE "Rank ( WJC )" = '6'