development of prior year incurred losses was $ 135.6 million unfavorable in 2006 , $ 26.4 million favorable in 2005 and $ 249.4 million unfavorable in 2004 . such losses were the result of the reserve development noted above , as well as inher- ent uncertainty in establishing loss and lae reserves . reserves for asbestos and environmental losses and loss adjustment expenses as of year end 2006 , 7.4% ( 7.4 % ) of reserves reflect an estimate for the company 2019s ultimate liability for a&e claims for which ulti- mate value cannot be estimated using traditional reserving techniques . the company 2019s a&e liabilities stem from mt . mckinley 2019s direct insurance business and everest re 2019s assumed reinsurance business . there are significant uncertainties in estimating the amount of the company 2019s potential losses from a&e claims . see item 7 , 201cmanagement 2019s discussion and analysis of financial condition and results of operations 2014asbestos and environmental exposures 201d and note 3 of notes to consolidated financial statements . mt . mckinley 2019s book of direct a&e exposed insurance is relatively small and homogenous . it also arises from a limited period , effective 1978 to 1984 . the book is based principally on excess liability policies , thereby limiting exposure analysis to a lim- ited number of policies and forms . as a result of this focused structure , the company believes that it is able to comprehen- sively analyze its exposures , allowing it to identify , analyze and actively monitor those claims which have unusual exposure , including policies in which it may be exposed to pay expenses in addition to policy limits or non-products asbestos claims . the company endeavors to be actively engaged with every insured account posing significant potential asbestos exposure to mt . mckinley . such engagement can take the form of pursuing a final settlement , negotiation , litigation , or the monitoring of claim activity under settlement in place ( 201csip 201d ) agreements . sip agreements generally condition an insurer 2019s payment upon the actual claim experience of the insured and may have annual payment caps or other measures to control the insurer 2019s payments . the company 2019s mt . mckinley operation is currently managing eight sip agreements , three of which were executed prior to the acquisition of mt . mckinley in 2000 . the company 2019s preference with respect to coverage settlements is to exe- cute settlements that call for a fixed schedule of payments , because such settlements eliminate future uncertainty . the company has significantly enhanced its classification of insureds by exposure characteristics over time , as well as its analysis by insured for those it considers to be more exposed or active . those insureds identified as relatively less exposed or active are subject to less rigorous , but still active management , with an emphasis on monitoring those characteristics , which may indicate an increasing exposure or levels of activity . the company continually focuses on further enhancement of the detailed estimation processes used to evaluate potential exposure of policyholders , including those that may not have reported significant a&e losses . everest re 2019s book of assumed reinsurance is relatively concentrated within a modest number of a&e exposed relationships . it also arises from a limited period , effectively 1977 to 1984 . because the book of business is relatively concentrated and the company has been managing the a&e exposures for many years , its claim staff is familiar with the ceding companies that have generated most of these liabilities in the past and which are therefore most likely to generate future liabilities . the company 2019s claim staff has developed familiarity both with the nature of the business written by its ceding companies and the claims handling and reserving practices of those companies . this level of familiarity enhances the quality of the company 2019s analysis of its exposure through those companies . as a result , the company believes that it can identify those claims on which it has unusual exposure , such as non-products asbestos claims , for concentrated attention . however , in setting reserves for its reinsurance liabilities , the company relies on claims data supplied , both formally and informally by its ceding companies and brokers . this furnished information is not always timely or accurate and can impact the accuracy and timeli- ness of the company 2019s ultimate loss projections . the following table summarizes the composition of the company 2019s total reserves for a&e losses , gross and net of reinsurance , for the years ended december 31: .
what is the average gross reserves from 2004 to 2006 in millions
( 1 ) additional reserves are case specific reserves determined by the company to be needed over and above those reported by the ceding company . 81790fin_a 4/13/07 11:08 am page 15 .