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', '2016', '2015', '2014'], ['cash provided by operating activities', '$ 7525', '$ 7344', '$ 7385'], ['cash used in investing activities', '-3393 ( 3393 )', '-4476 ( 4476 )', '-4249 ( 4249 )'], ['dividends paid', '-1879 ( 1879 )', '-2344 ( 2344 )', '-1632 ( 1632 )'], ['free cash flow', '$ 2253', '$ 524', '$ 1504']]
2017 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 , training and employee engagement , quality control , 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 2017 , we will continue to align resources with customer demand , maintain an efficient network , and ensure surge capability with our assets .f0b7 fuel prices 2013 fuel price projections for crude oil and natural gas continue to fluctuate in the current environment .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 increases or decreases in fuel price by approximately two months .continuing 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 could likely have a negative impact on other commodities such as coal and domestic drilling-related shipments .f0b7 capital plan 2013 in 2017 , we expect our capital plan to be approximately $ 3.1 billion , including expenditures for ptc , approximately 60 locomotives scheduled to be delivered , and intermodal containers and chassis , and freight cars .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 economic conditions in many of our market sectors continue to drive uncertainty with respect to our volume levels .we expect volume to grow in the low single digit range in 2017 compared to 2016 , but it will depend on the overall economy and market conditions .one of the more significant uncertainties is the outlook for energy markets , which will bring both challenges and opportunities .in the current environment , we expect continued margin improvement driven by continued pricing opportunities , ongoing productivity initiatives , and the ability to leverage our resources and strengthen our franchise .over the longer term , we expect the overall u.s .economy to continue to improve at a modest pace , with some markets outperforming others. .

Question: what was the percentage increase in the cash provided by operating activities from 2015 to 2016
Answer: 2.5%