in december , our board of directors ratified its authorization of a stock repurchase program in the amount of 1.5 million shares of our common stock . as of december 31 , 2010 no shares had been repurchased . we have paid dividends for 71 consecutive years with payments increasing each of the last 19 years . we paid total dividends of $ .54 per share in 2010 compared with $ .51 per share in 2009 . aggregate contractual obligations a summary of our contractual obligations as of december 31 , 2010 , is as follows: .
what percentage of total aggregate contractual obligations is composed of ?
as of december 31 , 2010 , the liability for uncertain income tax positions was $ 2.7 million . due to the high degree of uncertainty regarding timing of potential future cash flows associated with these liabilities , we are unable to make a reasonably reliable estimate of the amount and period in which these liabilities might be paid . we utilize blanket purchase orders to communicate expected annual requirements to many of our suppliers . requirements under blanket purchase orders generally do not become committed until several weeks prior to the company 2019s scheduled unit production . the purchase obligation amount presented above represents the value of commitments considered firm . results of operations our sales from continuing operations in 2010 were $ 1489.3 million surpassing 2009 sales of $ 1375.0 million by 8.3 percent . the increase in sales was due mostly to significantly higher sales in our water heater operations in china resulting from geographic expansion , market share gains and new product introductions as well as additional sales from our water treatment business acquired in november , 2009 . our sales from continuing operations were $ 1451.3 million in 2008 . the $ 76.3 million decline in sales from 2008 to 2009 was due to lower residential and commercial volume in north america , reflecting softness in the domestic housing market and a slowdown in the commercial water heater business and was partially offset by strong growth in water heater sales in china and improved year over year pricing . on december 13 , 2010 we entered into a definitive agreement to sell our electrical products company to regal beloit corporation for $ 700 million in cash and approximately 2.83 million shares of regal beloit common stock . the transaction , which has been approved by both companies' board of directors , is expected to close in the first half of 2011 . due to the pending sale , our electrical products segment has been accorded discontinued operations treatment in the accompanying financial statements . sales in 2010 , including sales of $ 701.8 million for our electrical products segment , were $ 2191.1 million . our gross profit margin for continuing operations in 2010 was 29.9 percent , compared with 28.7 percent in 2009 and 25.8 percent in 2008 . the improvement in margin from 2009 to 2010 was due to increased volume , cost containment activities and lower warranty costs which more than offset certain inefficiencies resulting from the may flood in our ashland city , tn water heater manufacturing facility . the increase in profit margin from 2008 to 2009 resulted from increased higher margin china water heater volume , aggressive cost reduction programs and lower material costs . selling , general and administrative expense ( sg&a ) was $ 36.9 million higher in 2010 than in 2009 . the increased sg&a , the majority of which was incurred in our china water heater operation , was associated with selling costs to support higher volume and new product lines . additional sg&a associated with our 2009 water treatment acquisition also contributed to the increase . sg&a was $ 8.5 million higher in 2009 than 2008 resulting mostly from an $ 8.2 million increase in our china water heater operation in support of higher volumes. .