Capital Expenditures
Our 2020 capital program includes capital to fund advanced networks and services, including expanding our core networks, adding capacity and density to our 4G LTE network in order to stay ahead of our customers’ increasing data demands and deploying our 5G network, transforming our structure to deploy the Intelligent Edge Network while reducing the cost to deliver services to our customers, and pursuing other opportunities to drive operating efficiencies. We expect that the new network architecture will simplify operations by eliminating legacy network elements, improve our 4G LTE coverage, speed the deployment of 5G technology, and create new enterprise opportunities in the business market. The level and the timing of the Company’s capital expenditures within these broad categories can vary significantly as a result of a variety of factors outside of our control, such as material weather events, equipment availability from vendors and permits from local governments. Capital expenditures for 2020 are expected to be in the range of $17.0 billion to $18.0 billion, including the continued investment in our 5G network. Capital expenditures were $17.9 billion in 2019 and $16.7 billion in 2018. We believe that we have significant discretion over the amount and timing of our capital expenditures on a Company-wide basis as we are not subject to any agreement that would require significant capital expenditures on a designated schedule or upon the occurrence of designated events.
Consolidated Financial Condition
We use the net cash generated from our operations to fund expansion and modernization of our networks, service and repay external financing, pay dividends, invest in new businesses and spectrum and, when appropriate, buy back shares of our outstanding common stock. Our sources of funds, primarily from operations and, to the extent necessary, from external financing arrangements, are sufficient to meet ongoing operating and investing requirements.
We expect that our capital spending requirements will continue to be financed primarily through internally generated funds. Debt or equity financing may be needed to fund additional investments or development activities or to maintain an appropriate capital structure to ensure our financial flexibility. Our cash and cash equivalents are held both domestically and internationally, and are invested to maintain principal and provide liquidity. See “Market Risk” for additional information regarding our foreign currency risk management strategies.
Our available external financing arrangements include an active commercial paper program, credit available under credit facilities and other bank lines of credit, vendor financing arrangements, issuances of registered debt or equity securities, U.S. retail medium-term notes and other capital market securities that are privately-placed or offered overseas. In addition, we monetize our device payment plan agreement receivables through asset-backed debt transactions.

(dollars in millions)
Years Ended December 31,
2019
2018
Cash flows provided by (used in)
Operating activities
$ 35,746
$ 34,339
Investing activities
(17,581)
(17,934)
Financing activities
(18,164)
(15,377)
Increase in cash, cash equivalents and restricted cash
$1
$ 1,028


Question: Analyse this data from a financial earnings document. What was the change in cash flow from operating activities from 2018 to 2019?
Choices:
35746
51123
0
-1407
1407
Correct choice index: 4