Query: IBM's operating margin in 2013 was what?
Context: Over the past decade, it has steadily shifted its business mix by exiting commoditizing markets such as PCs, hard disk drives and DRAMs and focusing on higher-value, more profitable markets such as business intelligence, data analytics, business continuity, security, cloud computing, virtualization and green solutions, resulting in a higher quality revenue stream and higher profit margins. IBM's operating margin expanded from 16.8% in 2004 to 24.3% in 2013, and net profit margins expanded from 9.0% in 2004 to 16.5% in 2013.