hollyfrontier corporation notes to consolidated financial statements continued .

( in thousands ): 2018: 148716
2019: 132547
2020: 119639
2021: 107400
2022: 102884
thereafter: 857454
total: 1468640

transportation and storage costs incurred under these agreements totaled $ 140.5 million , $ 135.1 million and $ 137.7 million for the years ended december 31 , 2017 , 2016 and 2015 , respectively . these amounts do not include contractual commitments under our long-term transportation agreements with hep , as all transactions with hep are eliminated in these consolidated financial statements . we have a crude oil supply contract that requires the supplier to deliver a specified volume of crude oil or pay a shortfall fee for the difference in the actual barrels delivered to us less the specified barrels per the supply contract . for the contract year ended august 31 , 2017 , the actual number of barrels delivered to us was substantially less than the specified barrels , and we recorded a reduction to cost of goods sold and accumulated a shortfall fee receivable of $ 26.0 million during this period . in september 2017 , the supplier notified us they are disputing the shortfall fee owed and in october 2017 notified us of their demand for arbitration . we offset the receivable with payments of invoices for deliveries of crude oil received subsequent to august 31 , 2017 , which is permitted under the supply contract . we believe the disputes and claims made by the supplier are without merit . in march , 2006 , a subsidiary of ours sold the assets of montana refining company under an asset purchase agreement ( 201capa 201d ) . calumet montana refining llc , the current owner of the assets , has submitted requests for reimbursement of approximately $ 20.0 million pursuant to contractual indemnity provisions under the apa for various costs incurred , as well as additional claims related to environmental matters . we have rejected most of the claims for payment , and this matter is scheduled for arbitration beginning in july 2018 . we have accrued the costs we believe are owed pursuant to the apa , and we estimate that any reasonably possible losses beyond the amounts accrued are not material . note 20 : segment information effective fourth quarter of 2017 , we revised our reportable segments to align with certain changes in how our chief operating decision maker manages and allocates resources to our business . accordingly , our tulsa refineries 2019 lubricants operations , previously reported in the refining segment , are now combined with the operations of our petro-canada lubricants business ( acquired february 1 , 2017 ) and reported in the lubricants and specialty products segment . our prior period segment information has been retrospectively adjusted to reflect our current segment presentation . our operations are organized into three reportable segments , refining , lubricants and specialty products and hep . our operations that are not included in the refining , lubricants and specialty products and hep segments are included in corporate and other . intersegment transactions are eliminated in our consolidated financial statements and are included in eliminations . corporate and other and eliminations are aggregated and presented under corporate , other and eliminations column . the refining segment represents the operations of the el dorado , tulsa , navajo , cheyenne and woods cross refineries and hfc asphalt ( aggregated as a reportable segment ) . refining activities involve the purchase and refining of crude oil and wholesale and branded marketing of refined products , such as gasoline , diesel fuel and jet fuel . these petroleum products are primarily marketed in the mid-continent , southwest and rocky mountain regions of the united states . hfc asphalt operates various asphalt terminals in arizona , new mexico and oklahoma. .

Questions:
what were the storage costs in 2017, in millions?
and what were they in 2016, also in millions?
what was, then, in millions, the total storage costs in the two years combined?
including 2015, what then becomes that total?
and what were the average storage costs between the three years, in millions?

Answers:
140.5
135.1
275.6
413.3
137.8