management 2019s discussion and analysis of financial condition and results of operations 2013 ( continued ) ( amounts in millions , except per share amounts ) corporate and other expenses increased slightly during 2013 by $ 3.5 to $ 140.8 compared to 2012 , primarily due to an increase in salaries and related expenses , mainly attributable to higher base salaries , benefits and temporary help , partially offset by lower severance expenses and a decrease in office and general expenses . liquidity and capital resources cash flow overview the following tables summarize key financial data relating to our liquidity , capital resources and uses of capital. .

years ended december 31 , 2014: net income adjusted to reconcile net income to net cashprovided by operating activities1: 831.2
net cash used in working capital b2: -131.1
changes in other non-current assets and liabilities using cash: -30.6
net cash provided by operating activities: 669.5
net cash used in investing activities: -200.8
net cash ( used in ) provided by financing activities: -343.9
years ended december 31 , 2013: net income adjusted to reconcile net income to net cashprovided by operating activities1: 598.4
net cash used in working capital b2: -9.6
changes in other non-current assets and liabilities using cash: 4.1
net cash provided by operating activities: 592.9
net cash used in investing activities: -224.5
net cash ( used in ) provided by financing activities: -1212.3
years ended december 31 , 2012: net income adjusted to reconcile net income to net cashprovided by operating activities1: 697.2
net cash used in working capital b2: -293.2
changes in other non-current assets and liabilities using cash: -46.8
net cash provided by operating activities: 357.2
net cash used in investing activities: -210.2
net cash ( used in ) provided by financing activities: 131.3

1 reflects net income adjusted primarily for depreciation and amortization of fixed assets and intangible assets , amortization of restricted stock and other non-cash compensation , non-cash ( gain ) loss related to early extinguishment of debt , and deferred income taxes . 2 reflects changes in accounts receivable , expenditures billable to clients , other current assets , accounts payable and accrued liabilities . operating activities net cash provided by operating activities during 2014 was $ 669.5 , which was an improvement of $ 76.6 as compared to 2013 , primarily as a result of an increase in net income , offset by an increase in working capital usage of $ 121.5 . due to the seasonality of our business , we typically generate cash from working capital in the second half of a year and use cash from working capital in the first half of a year , with the largest impacts in the first and fourth quarters . our net working capital usage in 2014 was impacted by our media businesses . net cash provided by operating activities during 2013 was $ 592.9 , which was an increase of $ 235.7 as compared to 2012 , primarily as a result of an improvement in working capital usage of $ 283.6 , offset by a decrease in net income . the improvement in working capital in 2013 was impacted by our media businesses and an ongoing focus on working capital management at our agencies . the timing of media buying on behalf of our clients affects our working capital and operating cash flow . in most of our businesses , our agencies enter into commitments to pay production and media costs on behalf of clients . to the extent possible we pay production and media charges after we have received funds from our clients . the amounts involved substantially exceed our revenues and primarily affect the level of accounts receivable , expenditures billable to clients , accounts payable and accrued liabilities . our assets include both cash received and accounts receivable from clients for these pass-through arrangements , while our liabilities include amounts owed on behalf of clients to media and production suppliers . our accrued liabilities are also affected by the timing of certain other payments . for example , while annual cash incentive awards are accrued throughout the year , they are generally paid during the first quarter of the subsequent year . investing activities net cash used in investing activities during 2014 primarily related to payments for capital expenditures and acquisitions . capital expenditures of $ 148.7 related primarily to computer hardware and software and leasehold improvements . we made payments of $ 67.8 related to acquisitions completed during 2014 , net of cash acquired. .

Questions:
what was the net cash provided by operating activities in 2014?
and what was it in 2013?
what was, then, the change over the year?
and how much does this change represent in relation to the 2013 net cash?

Answers:
669.5
592.9
76.6
12.9%