A 21-month-old lawsuit attacking fees charged to manage mutual funds controlled by two subsidiaries of Principal Financial Group Inc. has generated 30,000 pages of paper and resulted in the review of 150,000 electronic documents, with at least another 550,000 set for review, according to a status report filed recently in the case. According to court documents, lawyers for Principal and investors were confronted with a universe of 8 million electronic records and have winnowed the list. In the meantime, Principal has replaced one law firm with another as it defends itself against charges that the fees it  charge to manage mutual funds eat away at investor value. Babich Goldman P.C is the local representative for the plaintiffs. Whitfield & Eddy PLC is the local representative for Principal Management Corp. and Principal Funds Distributor Inc. The case is set for a 15-day bench trial in September 2012.