united parcel service , inc . and subsidiaries management's discussion and analysis of financial condition and results of operations liquidity and capital resources operating activities the following is a summary of the significant sources ( uses ) of cash from operating activities ( amounts in millions ) : .
what percentage of net cash from operating activities was derived from non-cash operating activities in 2013?
( a ) represents depreciation and amortization , gains and losses on derivative and foreign exchange transactions , deferred income taxes , provisions for uncollectible accounts , pension and postretirement benefit expense , stock compensation expense , impairment charges and other non-cash items . cash from operating activities remained strong throughout the 2011 to 2013 time period . operating cash flow was favorably impacted in 2013 , compared with 2012 , by lower contributions into our defined benefit pension and postretirement benefit plans ; however , this was partially offset by certain tnt express transaction-related charges , as well as changes in income tax receivables and payables . we paid a termination fee to tnt express of 20ac200 million ( $ 268 million ) under the agreement to terminate the merger protocol in the first quarter of 2013 . additionally , the cash payments for income taxes increased in 2013 compared with 2012 , and were impacted by the timing of current tax deductions . except for discretionary or accelerated fundings of our plans , contributions to our company-sponsored pension plans have largely varied based on whether any minimum funding requirements are present for individual pension plans . 2022 in 2013 , we did not have any required , nor make any discretionary , contributions to our primary company-sponsored pension plans in the u.s . 2022 in 2012 , we made a $ 355 million required contribution to the ups ibt pension plan . 2022 in 2011 , we made a $ 1.2 billion contribution to the ups ibt pension plan , which satisfied our 2011 contribution requirements and also approximately $ 440 million in contributions that would not have been required until after 2011 . 2022 the remaining contributions in the 2011 through 2013 period were largely due to contributions to our international pension plans and u.s . postretirement medical benefit plans . as discussed further in the 201ccontractual commitments 201d section , we have minimum funding requirements in the next several years , primarily related to the ups ibt pension , ups retirement and ups pension plans . as of december 31 , 2013 , the total of our worldwide holdings of cash and cash equivalents was $ 4.665 billion . approximately 45%-55% ( 45%-55 % ) of cash and cash equivalents was held by foreign subsidiaries throughout the year . the amount of cash held by our u.s . and foreign subsidiaries fluctuates throughout the year due to a variety of factors , including the timing of cash receipts and disbursements in the normal course of business . cash provided by operating activities in the united states continues to be our primary source of funds to finance domestic operating needs , capital expenditures , share repurchases and dividend payments to shareowners . to the extent that such amounts represent previously untaxed earnings , the cash held by foreign subsidiaries would be subject to tax if such amounts were repatriated in the form of dividends ; however , not all international cash balances would have to be repatriated in the form of a dividend if returned to the u.s . when amounts earned by foreign subsidiaries are expected to be indefinitely reinvested , no accrual for taxes is provided. .