what is the average of parent company guarantees from 2006-2007?
future minimum lease commitments for office premises and equipment under non-cancelable leases , along with minimum sublease rental income to be received under non-cancelable subleases , are as follows : period rent obligations sublease rental income net rent .

| Period | Rent Obligations | Sublease Rental Income | Net Rent |
| :--- | :--- | :--- | :--- |
| 2008 | $323.9 | $(40.9) | $283.0 |
| 2009 | 300.9 | (37.5) | 263.4 |
| 2010 | 267.7 | (31.0) | 236.7 |
| 2011 | 233.7 | (25.7) | 208.0 |
| 2012 | 197.9 | (20.2) | 177.7 |
| 2013 and thereafter | 871.0 | (33.1) | 837.9 |
| Total | $2,195.1 | $(188.4) | $2,006.7 |

guarantees we have certain contingent obligations under guarantees of certain of our subsidiaries ( 201cparent company guarantees 201d ) relating principally to credit facilities , guarantees of certain media payables and operating leases . the amount of such parent company guarantees was $ 327.1 and $ 327.9 as of december 31 , 2007 and 2006 , respectively . in the event of non-payment by the applicable subsidiary of the obligations covered by a guarantee , we would be obligated to pay the amounts covered by that guarantee . as of december 31 , 2007 , there are no material assets pledged as security for such parent company guarantees . contingent acquisition obligations we have structured certain acquisitions with additional contingent purchase price obligations in order to reduce the potential risk associated with negative future performance of the acquired entity . in addition , we have entered into agreements that may require us to purchase additional equity interests in certain consolidated and unconsolidated subsidiaries . the amounts relating to these transactions are based on estimates of the future financial performance of the acquired entity , the timing of the exercise of these rights , changes in foreign currency exchange rates and other factors . we have not recorded a liability for these items since the definitive amounts payable are not determinable or distributable . when the contingent acquisition obligations have been met and consideration is determinable and distributable , we record the fair value of this consideration as an additional cost of the acquired entity . however , we recognize deferred payments and purchases of additional interests after the effective date of purchase that are contingent upon the future employment of owners as compensation expense . compensation expense is determined based on the terms and conditions of the respective acquisition agreements and employment terms of the former owners of the acquired businesses . this future expense will not be allocated to the assets and liabilities acquired and is amortized over the required employment terms of the former owners . the following table details the estimated liability with respect to our contingent acquisition obligations and the estimated amount that would be paid under the options , in the event of exercise at the earliest exercise date . all payments are contingent upon achieving projected operating performance targets and satisfying other notes to consolidated financial statements 2014 ( continued ) ( amounts in millions , except per share amounts ) .

parent_company_guarantees = 327.1 + 327.9
average_guarantee = parent_company_guarantees / 2
answer = average_guarantee