content_image/142059.jpg content_image/142056.jpg content_image/142057.jpg content_image/142058.jpg
As of December 31, 2010 and 2009, investments with unrealized losses for greater than a 12-month period were not material to the Consolidated Balance Sheets and were not deemed to have other than temporary declines in value. 

The table below shows the cost and fair value of investments clas- sified as available-for-sale and held-to-maturity based on their contractual maturities as of December 31, 2010 and 2009. The expected maturities of certain fixed-income securities may differ from their contractual maturities because some of these holdings have call features that allow the issuers the right to prepay obliga- tions without penalties. 

<img src='content_image/142059.jpg'>

Held-to-maturity investments include a $1,600,000 certificate of deposit held as collateral against two bank guarantees for our office lease in Australia. 

The following table shows the realized gains and losses recorded in our Consolidated Statements of Income arising from sales of our investments classified as available-for-sale: 

<img src='content_image/142056.jpg'>

The following table shows the net unrealized gains (losses) on trad- ing securities as recorded in our Consolidated Statements of Income: 

<img src='content_image/142057.jpg'>

The fair value of our assets subject to fair value measurements and the necessary disclosures are as follows: 

<img src='content_image/142058.jpg'>

Level 1: Valuations based on quoted prices in active markets for identical assets or liabil- ities that we have the ability to access. 

Level 2: Valuations based on quoted prices in markets that are not active or for which all significant inputs are observable, either directly or indirectly. 

Level 3: Valuations based on inputs that are unobservable and significant to the overall fair value measurement. 

