pre_text: 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 ) .
post_text: aon corporation .
table: 2008 $317
table: 2009 275
table: 2010 236
table: 2011 214
table: 2012 191
table: Later years 597
table: Total minimum payments required $1,830
question: Analyse this data from a financial earnings document. what is the percentual decrease observed in the future minimum rental payments during 2008 and 2009?