content_image/174144.jpg content_image/174143.jpg content_image/174142.jpg
Stock-based compensation expense recognized in our Consolidated Statements of Income for the years ended December 31, 2013, 2012 and 2011 is based on RSUs and options ultimately expected to vest, and has been reduced for estimated forfeitures. Estimates for forfeiture rates are based upon historical experience and are evaluated quarterly. We expect our forfeiture rate for stock option awards to be approximately 2.5% annually. We estimated a 0% forfeiture rate for our RSUs and restricted stock due to the limited number of recipients and historical experience for these awards. 

## 4 Investments 

At December 31, 2013, we held the following securities and investments, recorded at either fair value or cost: 

<img src='content_image/174144.jpg'>

At December 31, 2012, we held the following securities and investments, recorded at either fair value or cost: 

<img src='content_image/174143.jpg'>

As of December 31, 2013, corporate and municipal fixed-rate bonds had the following contractual maturities: 

<img src='content_image/174142.jpg'>

