Charles and David Koch, the billionaire brothers who run Wichita, Kansas-based Koch Industries Inc., added $1.3 billion to their collective fortune yesterday on reports that U.S. industrial production gained more than forecast. The surge elevated their net worth to more than $100 billion, according to the Bloomberg Billionaires Index. The Koch s ascent comes as Freedom Partners, one of their fundraising networks, last week aired its first batch of television ads targeted at this year s U.S. Senate races, including commercials knocking Democratic Senator Mark Udall of Colorado and Representative Bruce Braley of Iowa for supporting President Barack Obama s health-care law.