in our primary disbursement accounts which were reclassified as accounts payable and other accrued liabilities on our consolidated balance sheet . concentration of credit risk financial instruments that potentially subject us to concentrations of credit risk consist of cash and cash equivalents , trade accounts receivable and derivative instruments . we place our cash and cash equivalents with high quality financial institutions . such balances may be in excess of fdic insured limits . in order to manage the related credit exposure , we continually monitor the credit worthiness of the financial institutions where we have deposits . concentrations of credit risk with respect to trade accounts receivable are limited due to the wide variety of customers and markets in which we provide services , as well as the dispersion of our operations across many geographic areas . we provide services to commercial , industrial , municipal and residential customers in the united states and puerto rico . we perform ongoing credit evaluations of our customers , but do not require collateral to support customer receivables . we establish an allowance for doubtful accounts based on various factors including the credit risk of specific customers , age of receivables outstanding , historical trends , economic conditions and other information . no customer exceeded 5% ( 5 % ) of our outstanding accounts receivable balance at december 31 , 2009 or 2008 . accounts receivable , net of allowance for doubtful accounts accounts receivable represent receivables from customers for collection , transfer , recycling , disposal and other services . our receivables are recorded when billed or when the related revenue is earned , if earlier , and represent claims against third parties that will be settled in cash . the carrying value of our receivables , net of the allowance for doubtful accounts , represents their estimated net realizable value . provisions for doubtful accounts are evaluated on a monthly basis and are recorded based on our historical collection experience , the age of the receivables , specific customer information and economic conditions . we also review outstanding balances on an account-specific basis . in general , reserves are provided for accounts receivable in excess of ninety days old . past due receivable balances are written-off when our collection efforts have been unsuccess- ful in collecting amounts due . the following table reflects the activity in our allowance for doubtful accounts for the years ended december 31 , 2009 , 2008 and 2007: .
as of december 312019 what was the percentage of restricted cash that was proceeds from the issuance of tax-exempt bonds
subsequent to our acquisition of allied , we recorded a provision for doubtful accounts of $ 14.2 million to adjust the allowance acquired from allied to conform to republic 2019s accounting policies . we also recorded $ 5.4 million to provide for specific bankruptcy exposures in 2008 . in 2007 , we recorded a $ 4.3 million reduction in our allowance for doubtful accounts as a result of refining our estimate of the allowance based on our historical collection experience . restricted cash as of december 31 , 2009 , we had $ 236.6 million of restricted cash , of which $ 93.1 million was proceeds from the issuance of tax-exempt bonds and other tax-exempt financings and will be used to fund capital republic services , inc . and subsidiaries notes to consolidated financial statements , continued .