Read the following texts and table with financial data from an S&P 500 earnings report carefully.Based on the question-answer history (if provided), answer the last question. The answer may require mathematical calculation based on the data provided.

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 ) . <table class='wikitable'><tr><td>1</td><td>2008</td><td>$ 317</td></tr><tr><td>2</td><td>2009</td><td>275</td></tr><tr><td>3</td><td>2010</td><td>236</td></tr><tr><td>4</td><td>2011</td><td>214</td></tr><tr><td>5</td><td>2012</td><td>191</td></tr><tr><td>6</td><td>later years</td><td>597</td></tr><tr><td>7</td><td>total minimum payments required</td><td>$ 1830</td></tr></table> aon corporation .
Question: what is the difference between the net rent expense of the years 2009 and 2008?

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