generate cash without additional external financings .
free cash flow should be considered in addition to , rather than as a substitute for , cash provided by operating activities .
the following table reconciles cash provided by operating activities ( gaap measure ) to free cash flow ( non-gaap measure ) : millions 2014 2013 2012 .

<i>Millions</i>
<i>2014</i>
<i>2013</i>
<i>2012</i>
Cash provided by operating activities
$7,385
$6,823
$6,161
Cash used in investing activities
(4,249)
(3,405)
(3,633)
Dividends paid
(1,632)
(1,333)
(1,146)
Free cash flow
$1,504
$2,085
$1,382

2015 outlook f0b7 safety 2013 operating a safe railroad benefits all our constituents : our employees , customers , shareholders and the communities we serve .
we will continue using a multi-faceted approach to safety , utilizing technology , risk assessment , quality control , training and employee engagement , and targeted capital investments .
we will continue using and expanding the deployment of total safety culture and courage to care throughout our operations , which allows us to identify and implement best practices for employee and operational safety .
we will continue our efforts to increase detection of rail defects ; improve or close crossings ; and educate the public and law enforcement agencies about crossing safety through a combination of our own programs ( including risk assessment strategies ) , industry programs and local community activities across our network .
f0b7 network operations 2013 in 2015 , we will continue to add resources to support growth , improve service , and replenish our surge capability .
f0b7 fuel prices 2013 with the dramatic drop in fuel prices at the end of 2014 , there is even more uncertainty around the projections of fuel prices .
we again could see volatile fuel prices during the year , as they are sensitive to global and u.s .
domestic demand , refining capacity , geopolitical events , weather conditions and other factors .
as prices fluctuate there will be a timing impact on earnings , as our fuel surcharge programs trail fluctuations in fuel price by approximately two months .
lower fuel prices could have a positive impact on the economy by increasing consumer discretionary spending that potentially could increase demand for various consumer products that we transport .
alternatively , lower fuel prices will likely have a negative impact on other commodities such as coal , frac sand and crude oil shipments .
f0b7 capital plan 2013 in 2015 , we expect our capital plan to be approximately $ 4.3 billion , including expenditures for ptc and 218 locomotives .
the capital plan may be revised if business conditions warrant or if new laws or regulations affect our ability to generate sufficient returns on these investments .
( see further discussion in this item 7 under liquidity and capital resources 2013 capital plan. ) f0b7 financial expectations 2013 we expect the overall u.s .
economy to continue to improve at a moderate pace .
one of the biggest uncertainties is the outlook for energy markets , which will bring both challenges and opportunities .
on balance , we expect to see positive volume growth for 2015 versus the prior year .
in the current environment , we expect continued margin improvement driven by continued pricing opportunities , ongoing productivity initiatives and the ability to leverage our resources as we improve the fluidity of our network. .

Question: Analyse this data from a financial earnings document. what was the percentage change in free cash flow from 2013 to 2014?
Choices:
-0.00028
0.15992
-0.27866
-3.58864
1.50408
Correct choice index: 2