Please answer the given financial question based on the context.
Context: supplementary information on oil and gas producing activities ( unaudited ) changes in the standardized measure of discounted future net cash flows .
|( in millions )|2009|2008|2007|
|sales and transfers of oil and gas produced net of production andadministrative costs|$ -4876 ( 4876 )|$ -6863 ( 6863 )|$ -4613 ( 4613 )|
|net changes in prices and production and administrative costs related tofuture production|4840|-18683 ( 18683 )|12344|
|extensions discoveries and improved recovery less related costs|1399|663|1816|
|development costs incurred during the period|2786|1774|1569|
|changes in estimated future development costs|-3641 ( 3641 )|-1436 ( 1436 )|-1706 ( 1706 )|
|revisions of previous quantity estimates|5110|85|166|
|net changes in purchases and sales of minerals in place|-159 ( 159 )|-13 ( 13 )|23|
|accretion of discount|787|2724|1696|
|net change in income taxes|-4441 ( 4441 )|12633|-6647 ( 6647 )|
|timing and other|-149 ( 149 )|184|-31 ( 31 )|
|net change for the year|1656|-8932 ( 8932 )|4617|
|beginning of the year|4035|12967|8350|
|end of year|$ 5691|$ 4035|$ 12967|
|net change for the year from discontinued operations|$ -|$ 284|$ 528|
.
Question: in millions , what was the average net change in discounted future cash flows for the three year period?
Answer:
-886.33333