NSS Labs: IE9 blocks 5x more threats than Firefox, Chrome & Safari

NSS Labs, a reputable security research center, has just released its 2010 Q3 Browser Security report. In this report the attack protection found in IE8 jumped from 85% to 95%, and IE9 jumped from 90% to 99%!

 

Thus IE9 blocks 5x as many attacks as Firefox, 9x as Safari, and 33x as Chrome.

How do the Internet Explorer does this?