According to this article, "6.8 million people currently live in Israel, 5.5 million of them - Jewish."  Zechariah 13:8-9 says, "And it shall come to pass in all the land, saith the Lord, saith the Lord, two parts therein shall be cut off and die; but the third part shall be left therein.  And I will bring the third part through the fire, and will refine them as gold is tried: they shall call upon my name, and I will hear them: I will say, It is my people; and they shall say, The Lord is my God."  If there are only 5,500,000 Jewish people in all the land, then 1/3 would amount to 1,833,333 surviving with the rest dying.  However, if there were 13,000,000 people in all the land since there are 13 million Jews worldwide, then 4,333,333 Jewish people would survive, and the rest would die.
 
http://www.jpost.com/servlet/Satellite?pagename=JPost/JPArticle/ShowFull&cid=1095131864652&p=1078397702269