human
in summary, our cash flows for each period were as follows:.
| (In Millions) | 2013 | 2012 | 2011 |
| --------- | --------- | --------- | --------- |
| Net cash provided by operating activities | $20,776 | $18,884 | $20,963 |
| Net cash used for investing activities | (18,073) | (14,060) | (10,301) |
| Net cash used for financing activities | (5,498) | (1,408) | (11,100) |
| Effect of exchange rate fluctuations on cash and cash equivalents | (9) | (3) | 5 |
| Net increase (decrease) in cash and cash equivalents | $(2,804) | $3,413 | $(433) |
operating activities cash provided by operating activities is net income adjusted for certain non-cash items and changes in certain assets and liabilities. for 2013 compared to 2012, the $1.9 billion increase in cash provided by operating activities was due to changes in working capital, partially offset by lower net income in 2013. income taxes paid, net of refunds, in 2013 compared to 2012 were $1.1 billion lower due to lower income before taxes in 2013 and 2012 income tax overpayments. changes in assets and liabilities as of december 28, 2013, compared to december 29, 2012, included lower income taxes payable and receivable resulting from a reduction in taxes due in 2013, and lower inventories due to the sell-through of older-generation products, partially offset by the ramp of 4th generation intel core processor family products. for 2013, our three largest customers accounted for 44% (44%) of our net revenue (43% (43%) in 2012 and 2011), with hewlett- packard company accounting for 17% (17%) of our net revenue (18% (18%) in 2012 and 19% (19%) in 2011), dell accounting for 15% (15%) of our net revenue (14% (14%) in 2012 and 15% (15%) in 2011), and lenovo accounting for 12% (12%) of our net revenue (11% (11%) in 2012 and 9% (9%) in 2011). these three customers accounted for 34% (34%) of our accounts receivable as of december 28, 2013 (33% (33%) as of december 29, 2012). for 2012 compared to 2011, the $2.1 billion decrease in cash provided by operating activities was due to lower net income and changes in our working capital, partially offset by adjustments for non-cash items. the adjustments for noncash items were higher due primarily to higher depreciation in 2012 compared to 2011, partially offset by increases in non-acquisition-related deferred tax liabilities as of december 31, 2011. investing activities investing cash flows consist primarily of capital expenditures; investment purchases, sales, maturities, and disposals; as well as cash used for acquisitions. the increase in cash used for investing activities in 2013 compared to 2012 was primarily due to an increase in purchases of available-for-sale investments and a decrease in maturities and sales of trading assets, partially offset by an increase in maturities and sales of available-for-sale investments and a decrease in purchases of licensed technology and patents. our capital expenditures were $10.7 billion in 2013 ($11.0 billion in 2012 and $10.8 billion in 2011). cash used for investing activities increased in 2012 compared to 2011 primarily due to net purchases of available- for-sale investments and trading assets in 2012, as compared to net maturities and sales of available-for-sale investments and trading assets in 2011, partially offset by a decrease in cash paid for acquisitions. net purchases of available-for-sale investments in 2012 included our purchase of $3.2 billion of equity securities in asml in q3 2012. financing activities financing cash flows consist primarily of repurchases of common stock, payment of dividends to stockholders, issuance and repayment of long-term debt, and proceeds from the sale of shares through employee equity incentive plans. table of contents management 2019s discussion and analysis of financial condition and results of operations (continued).
Please answer the following question with expressions if necessary.
what was the percent change?
assistant
subtract(18884, 20963), divide(#0, 20963)