credit commitments the table below summarizes citigroup 2019s other commitments as of december 31 , 2008 and december 31 , 2007 .in millions of dollars u.s .outside december 31 , december 31 .
[['in millions of dollars', 'u.s .', 'outside u.s .', 'december 31 2008', 'december 31 2007'], ['commercial and similar letters of credit', '$ 2187', '$ 6028', '$ 8215', '$ 9175'], ['one- to four-family residential mortgages', '628', '309', '937', '4587'], ['revolving open-end loans secured by one- to four-family residential properties', '22591', '2621', '25212', '35187'], ['commercial real estate construction and land development', '2084', '618', '2702', '4834'], ['credit card lines', '867261', '135176', '1002437', '1103535'], ['commercial and other consumer loan commitments', '217818', '92179', '309997', '473631'], ['total', '$ 1112569', '$ 236931', '$ 1349500', '$ 1630949']]
the majority of unused commitments are contingent upon customers 2019 maintaining specific credit standards .commercial commitments generally have floating interest rates and fixed expiration dates and may require payment of fees .such fees ( net of certain direct costs ) are deferred and , upon exercise of the commitment , amortized over the life of the loan or , if exercise is deemed remote , amortized over the commitment period .commercial and similar letters of credit a commercial letter of credit is an instrument by which citigroup substitutes its credit for that of a customer to enable the customer to finance the purchase of goods or to incur other commitments .citigroup issues a letter on behalf of its client to a supplier and agrees to pay the supplier upon presentation of documentary evidence that the supplier has performed in accordance with the terms of the letter of credit .when drawn , the customer then is required to reimburse citigroup .one- to four-family residential mortgages a one- to four-family residential mortgage commitment is a written confirmation from citigroup to a seller of a property that the bank will advance the specified sums enabling the buyer to complete the purchase .revolving open-end loans secured by one- to four-family residential properties revolving open-end loans secured by one- to four-family residential properties are essentially home equity lines of credit .a home equity line of credit is a loan secured by a primary residence or second home to the extent of the excess of fair market value over the debt outstanding for the first mortgage .commercial real estate , construction and land development commercial real estate , construction and land development include unused portions of commitments to extend credit for the purpose of financing commercial and multifamily residential properties as well as land development projects .both secured-by-real-estate and unsecured commitments are included in this line .in addition , undistributed loan proceeds , where there is an obligation to advance for construction progress , payments are also included in this line .however , this line only includes those extensions of credit that once funded will be classified as loans on the consolidated balance sheet .credit card lines citigroup provides credit to customers by issuing credit cards .the credit card lines are unconditionally cancellable by the issuer .commercial and other consumer loan commitments commercial and other consumer loan commitments include commercial commitments to make or purchase loans , to purchase third-party receivables and to provide note issuance or revolving underwriting facilities .amounts include $ 140 billion and $ 259 billion with an original maturity of less than one year at december 31 , 2008 and december 31 , 2007 , respectively .in addition , included in this line item are highly leveraged financing commitments which are agreements that provide funding to a borrower with higher levels of debt ( measured by the ratio of debt capital to equity capital of the borrower ) than is generally considered normal for other companies .this type of financing is commonly employed in corporate acquisitions , management buy-outs and similar transactions. .

Question: what percentage of citigroup 2019s total other commitments as of december 31 , 2008 are outside the u.s.?
Answer: 18%