{"pre_text": ["2015 vs .", "2014 on a gaap basis , the effective tax rate was 24.0% ( 24.0 % ) and 27.1% ( 27.1 % ) in 2015 and 2014 , respectively .", "the effective tax rate was higher in fiscal year 2014 primarily due to the goodwill impairment charge of $ 305.2 , which was not deductible for tax purposes , and the chilean tax reform enacted in september 2014 which increased income tax expense by $ 20.6 .", "these impacts were partially offset by an income tax benefit of $ 51.6 associated with losses from transactions and a tax election in a non-u.s .", "subsidiary .", "refer to note 10 , goodwill , and note 23 , income taxes , to the consolidated financial statements for additional information .", "on a non-gaap basis , the effective tax rate was 24.2% ( 24.2 % ) and 24.1% ( 24.1 % ) in 2015 and 2014 , respectively .", "discontinued operations on 29 march 2016 , the board of directors approved the company 2019s exit of its energy-from-waste ( efw ) business .", "as a result , efforts to start up and operate its two efw projects located in tees valley , united kingdom , have been discontinued .", "the decision to exit the business and stop development of the projects was based on continued difficulties encountered and the company 2019s conclusion , based on testing and analysis completed during the second quarter of fiscal year 2016 , that significant additional time and resources would be required to make the projects operational .", "in addition , the decision allows the company to execute its strategy of focusing resources on its core industrial gases business .", "the efw segment has been presented as a discontinued operation .", "prior year efw business segment information has been reclassified to conform to current year presentation .", "in fiscal 2016 , our loss from discontinued operations , net of tax , of $ 884.2 primarily resulted from the write down of assets to their estimated net realizable value and to record a liability for plant disposition and other costs .", "income tax benefits related only to one of the projects , as the other did not qualify for a local tax deduction .", "the loss from discontinued operations also includes land lease costs , commercial and administrative costs , and costs incurred for ongoing project exit activities .", "we expect additional exit costs of $ 50 to $ 100 to be recorded in future periods .", "in fiscal 2015 , our loss from discontinued operations , net of tax , related to efw was $ 6.8 .", "this resulted from costs for land leases and commercial and administrative expenses .", "in fiscal 2014 , our loss from discontinued operations , net of tax , was $ 2.9 .", "this included a loss , net of tax , of $ 7.5 for the cost of efw land leases and commercial and administrative expenses .", "this loss was partially offset by a gain of $ 3.9 for the sale of the remaining homecare business and settlement of contingencies related to a sale of a separate portion of the business to the linde group in 2012 .", "refer to note 4 , discontinued operations , for additional details .", "segment analysis industrial gases 2013 americas ."], "post_text": ["."], "table": [["", "2016", "2015", "2014"], ["sales", "$ 3343.6", "$ 3693.9", "$ 4078.5"], ["operating income", "895.2", "808.4", "762.6"], ["operating margin", "26.8% ( 26.8 % )", "21.9% ( 21.9 % )", "18.7% ( 18.7 % )"], ["equity affiliates 2019 income", "52.7", "64.6", "60.9"], ["adjusted ebitda", "1390.4", "1289.9", "1237.9"], ["adjusted ebitda margin", "41.6% ( 41.6 % )", "34.9% ( 34.9 % )", "30.4% ( 30.4 % )"]], "table_ori": [["", "2016", "2015", "2014"], ["Sales", "$3,343.6", "$3,693.9", "$4,078.5"], ["Operating income", "895.2", "808.4", "762.6"], ["Operating margin", "26.8%", "21.9%", "18.7%"], ["Equity affiliates’ income", "52.7", "64.6", "60.9"], ["Adjusted EBITDA", "1,390.4", "1,289.9", "1,237.9"], ["Adjusted EBITDA margin", "41.6%", "34.9%", "30.4%"]]}

Question: what is the increase in the operating margin observed in 2015 and 2016?
Evidence:
table_3: the operating margin of 2016 is 26.8% ( 26.8 % ) ; the operating margin of 2015 is 21.9% ( 21.9 % ) ; the operating margin of 2014 is 18.7% ( 18.7 % ) ;
Program: subtract(26.8%, 21.9%)
Answer:
str_answer: 4.9%
exe_answer: 0.049