Please answer the given financial question based on the context.
Context: notes to consolidated financial statements at december 31 , 2007 , future minimum rental payments required under operating leases for continuing operations that have initial or remaining noncancelable lease terms in excess of one year , net of sublease rental income , most of which pertain to real estate leases , are as follows : ( millions ) .
|2008|$ 317|
|2009|275|
|2010|236|
|2011|214|
|2012|191|
|later years|597|
|total minimum payments required|$ 1830|
aon corporation .
Question: what is the percentual decrease observed in the future minimum rental payments during 2008 and 2009?
Answer:
-0.13249