We continued to return cash to shareholders with our quarterly dividend of approximately $97 million and our share repurchase activity, which totaled $23 million in the fourth quarter. We returned $509 million of cash to shareholders in 2015 with quarterly dividends totaling $378 million and share repurchases of $131 million. We have $169 million remaining in the share repurchase program authorized through December 31, 2016, and expect to repurchase as business and market conditions warrant. We ended the quarter with cash and marketable securities of about $2.4 billion.
2016 Guidance:
| 2016 Guidance | |||||||||
| Revenue | ~$2.82 B | ||||||||
| Gross Margin | ~54.5% | ||||||||
| Operating Income | ~510M | ||||||||
| Operating Margin | ~18% | ||||||||
| Tax Rate | ~20.5% | ||||||||
| EPS (Pro Forma) | ~$2.25 | ||||||||
