borrowings reflect net proceeds received from the issuance of senior notes in june 2015 . see liquidity and capital resources below for additional information . in november 2015 , we repaid our $ 1 billion 0.90% ( 0.90 % ) senior notes upon maturity . in october 2015 , we announced an adjustment to our quarterly dividend . see capital requirements below for additional information . additions to property , plant and equipment are our most significant use of cash and cash equivalents . the following table shows capital expenditures related to continuing operations by segment and reconciles to additions to property , plant and equipment as presented in the consolidated statements of cash flows for 2015 , 2014 and 2013: .

Table:
( in millions ) | year ended december 31 , 2015 | year ended december 31 , 2014 | year ended december 31 , 2013
north america e&p | $ 2553 | $ 4698 | $ 3649
international e&p | 368 | 534 | 456
oil sands mining ( a ) | -10 ( 10 ) | 212 | 286
corporate | 25 | 51 | 58
total capital expenditures | 2936 | 5495 | 4449
change in capital expenditure accrual | 540 | -335 ( 335 ) | -6 ( 6 )
additions to property plant and equipment | $ 3476 | $ 5160 | $ 4443
( a ) reflects reimbursements earned from the governments of canada and alberta related to funds previously expended for quest ccs capital equipment .
quest ccs was successfully completed and commissioned in the fourth quarter of 2015 .
during 2014 , we acquired 29 million shares at a cost of $ 1 billion and in 2013 acquired 14 million shares at a cost of $ 500 million .
there were no share repurchases in 2015 .
see item 8 .
financial statements and supplementary data 2013 note 23 to the consolidated financial statements for discussion of purchases of common stock .
liquidity and capital resources on june 10 , 2015 , we issued $ 2 billion aggregate principal amount of unsecured senior notes which consist of the following series : 2022 $ 600 million of 2.70% ( 2.70 % ) senior notes due june 1 , 2020 2022 $ 900 million of 3.85% ( 3.85 % ) senior notes due june 1 , 2025 2022 $ 500 million of 5.20% ( 5.20 % ) senior notes due june 1 , 2045 interest on each series of senior notes is payable semi-annually beginning december 1 , 2015 .
we used the aggregate net proceeds to repay our $ 1 billion 0.90% ( 0.90 % ) senior notes on november 2 , 2015 , and the remainder for general corporate purposes .
in may 2015 , we amended our $ 2.5 billion credit facility to increase the facility size by $ 500 million to a total of $ 3.0 billion and extend the maturity date by an additional year such that the credit facility now matures in may 2020 .
the amendment additionally provides us the ability to request two one-year extensions to the maturity date and an option to increase the commitment amount by up to an additional $ 500 million , subject to the consent of any increasing lenders .
the sub-facilities for swing-line loans and letters of credit remain unchanged allowing up to an aggregate amount of $ 100 million and $ 500 million , respectively .
fees on the unused commitment of each lender , as well as the borrowing options under the credit facility , remain unchanged .
our main sources of liquidity are cash and cash equivalents , internally generated cash flow from operations , capital market transactions , our committed revolving credit facility and sales of non-core assets .
our working capital requirements are supported by these sources and we may issue either commercial paper backed by our $ 3.0 billion revolving credit facility or draw on our $ 3.0 billion revolving credit facility to meet short-term cash requirements or issue debt or equity securities through the shelf registration statement discussed below as part of our longer-term liquidity and capital management .
because of the alternatives available to us as discussed above , we believe that our short-term and long-term liquidity is adequate to fund not only our current operations , but also our near-term and long-term funding requirements including our capital spending programs , dividend payments , defined benefit plan contributions , repayment of debt maturities and other amounts that may ultimately be paid in connection with contingencies .
general economic conditions , commodity prices , and financial , business and other factors could affect our operations and our ability to access the capital markets .
a downgrade in our credit ratings could negatively impact our cost of capital and our ability to access the capital markets , increase the interest rate and fees we pay on our unsecured revolving credit facility , restrict our access to the commercial paper market , or require us to post letters of credit or other forms of collateral for certain .

Question: by how much did additions to property plant and equipment decrease from 2013 to 2015?
Answer: -21.8%
Calculation: subtract(3476, 4443), divide(#0, 4443)