Israel’s anti-missile defense system intercepted 85% of the rockets that Gaza terrorists fired at civilians during Operation Pillar of Defense. But towards the end of the conflict, Rafael engineers managed to improve this to 100% – and halted the firing of the second (backup) missile.
http://fullcomment.nationalpost.com/2012/12/30/matt-gurney-bad-news-hamas-israels-iron-dome-gets-better-every-day/