Please answer the given financial question based on the context.
Context: table of contents valero energy corporation and subsidiaries notes to consolidated financial statements ( continued ) cash flow hedges cash flow hedges are used to hedge price volatility in certain forecasted feedstock and refined product purchases , refined product sales , and natural gas purchases . the objective of our cash flow hedges is to lock in the price of forecasted feedstock , product or natural gas purchases or refined product sales at existing market prices that we deem favorable . as of december 31 , 2011 , we had the following outstanding commodity derivative instruments that were entered into to hedge forecasted purchases or sales of crude oil and refined products . the information presents the notional volume of outstanding contracts by type of instrument and year of maturity ( volumes in thousands of barrels ) . notional contract volumes by year of maturity derivative instrument 2012 .
|derivative instrument|notional contract volumes by year of maturity 2012|
|crude oil and refined products:||
|swaps 2013 long|5961|
|swaps 2013 short|5961|
|futures 2013 long|38201|
|futures 2013 short|36637|
|physical contracts 2013 short|1564|
.
Question: how many more long future notional contracts mature by 2012 than short futures?
Answer:
1564.0