amount of commitment expiration per period other commercial commitments after millions of dollars total 2010 2011 2012 2013 2014 2014 .

Table:
other commercial commitmentsmillions of dollars | total | amount of commitment expiration per period 2010 | amount of commitment expiration per period 2011 | amount of commitment expiration per period 2012 | amount of commitment expiration per period 2013 | amount of commitment expiration per period 2014 | amount of commitment expiration per period after 2014
credit facilities [a] | $ 1900 | $ - | $ - | $ 1900 | $ - | $ - | $ -
sale of receivables [b] | 600 | 600 | - | - | - | - | -
guarantees [c] | 416 | 29 | 76 | 24 | 8 | 214 | 65
standby letters of credit [d] | 22 | 22 | - | - | - | - | -
total commercial commitments | $ 2938 | $ 651 | $ 76 | $ 1924 | $ 8 | $ 214 | $ 65
[a] none of the credit facility was used as of december 31 , 2009 .
[b] $ 400 million of the sale of receivables program was utilized at december 31 , 2009 .
[c] includes guaranteed obligations related to our headquarters building , equipment financings , and affiliated operations .
[d] none of the letters of credit were drawn upon as of december 31 , 2009 .
off-balance sheet arrangements sale of receivables 2013 the railroad transfers most of its accounts receivable to union pacific receivables , inc .
( upri ) , a bankruptcy-remote subsidiary , as part of a sale of receivables facility .
upri sells , without recourse on a 364-day revolving basis , an undivided interest in such accounts receivable to investors .
the total capacity to sell undivided interests to investors under the facility was $ 600 million and $ 700 million at december 31 , 2009 and 2008 , respectively .
the value of the outstanding undivided interest held by investors under the facility was $ 400 million and $ 584 million at december 31 , 2009 and 2008 , respectively .
during 2009 , upri reduced the outstanding undivided interest held by investors due to a decrease in available receivables .
the value of the undivided interest held by investors is not included in our consolidated financial statements .
the value of the undivided interest held by investors was supported by $ 817 million and $ 1015 million of accounts receivable held by upri at december 31 , 2009 and 2008 , respectively .
at december 31 , 2009 and 2008 , the value of the interest retained by upri was $ 417 million and $ 431 million , respectively .
this retained interest is included in accounts receivable in our consolidated financial statements .
the interest sold to investors is sold at carrying value , which approximates fair value , and there is no gain or loss recognized from the transaction .
the value of the outstanding undivided interest held by investors could fluctuate based upon the availability of eligible receivables and is directly affected by changing business volumes and credit risks , including default and dilution .
if default or dilution ratios increase one percent , the value of the outstanding undivided interest held by investors would not change as of december 31 , 2009 .
should our credit rating fall below investment grade , the value of the outstanding undivided interest held by investors would be reduced , and , in certain cases , the investors would have the right to discontinue the facility .
the railroad services the sold receivables ; however , the railroad does not recognize any servicing asset or liability , as the servicing fees adequately compensate us for these responsibilities .
the railroad collected approximately $ 13.8 billion and $ 17.8 billion during the years ended december 31 , 2009 and 2008 , respectively .
upri used certain of these proceeds to purchase new receivables under the facility .
the costs of the sale of receivables program are included in other income and were $ 9 million , $ 23 million , and $ 35 million for 2009 , 2008 , and 2007 , respectively .
the costs include interest , which will vary based on prevailing commercial paper rates , program fees paid to banks , commercial paper issuing costs , and fees for unused commitment availability .
the decrease in the 2009 costs was primarily attributable to lower commercial paper rates and a decrease in the outstanding interest held by investors. .

Question: what percentage of total commercial commitments are sale of receivables?
Answer: 20%
Calculation: divide(600, 2938)