12 months

The amount of time Microsoft CEO Steve Ballmer has left at the helm of the company. Ballmer announced today that he will stay on until the tech giant finds his replacement. (USA Today)

1 in 5

One in five Americans do not use the Internet at all. Private companies (such as Facebook) and public agencies (such as the FCC) are trying to change this. (NYT)

78.9%

The percent of daily active Facebook users who visit the social networking site from their mobile devices. Test your knowledge of the week’s tech numbers with our quiz Silicon Tally. (Marketplace)