Gain on Previously Held Equity Interest On 30 December 2014, we acquired our partner’s equity ownership interest in a liquefied atmospheric industrial gases production joint venture in North America for $22.6, which increased our ownership from 50% to 100%.
The transaction was accounted for as a business combination, and subsequent to the acquisition, the results were consolidated within our Industrial Gases – Americas segment.
We recorded a gain of $17.9 ($11.2 after-tax, or $.05 per share) as a result of revaluing our previously held equity interest to fair value as of the acquisition date.
Refer to Note 6, Business Combination, to the consolidated financial statements for additional details.
Other Income (Expense), Net Items recorded to other income (expense), net arise from transactions and events not directly related to our principal income earning activities.
The detail of other income (expense), net is presented in Note 23, Supplemental Information, to the consolidated financial statements.2017 vs.  2016 Other income (expense), net of $121.0 increased $71.6, primarily due to income from transition services agreements with Versum and Evonik, income from the sale of assets and investments, including a gain of $12.2 ($7.6 after-tax, or $.03 per share) resulting from the sale of a parcel of land, and a favorable foreign exchange impact.2016 vs.  2015 Other income (expense), net of $49.4 increased $3.9, primarily due to lower foreign exchange losses, favorable contract settlements, and receipt of a government subsidy.
Fiscal year 2015 included a gain of $33.6 ($28.3 after tax, or $.13 per share) resulting from the sale of two parcels of land.
No other individual items were significant in comparison to fiscal year 2015.
Interest Expense
## Table 0 ##
2017 vs.  2016 Interest incurred decreased $8.3 as the impact from a lower average debt balance of $26 was partially offset by the impact from a higher average interest rate on the debt portfolio of $19.
The change in capitalized interest was driven by a decrease in the carrying value of projects under construction, primarily as a result of our decision to exit from the Energy-from-Waste business.2016 vs.  2015 Interest incurred decreased $4.0.
The decrease primarily resulted from a stronger U. S.  dollar on the translation of foreign currency interest of $6, partially offset by a higher average debt balance of $2.
The change in capitalized interest was driven by a decrease in the carrying value of projects under construction, primarily as a result of our exit from the Energy-from-Waste business.
Other Non-Operating Income (Expense), Net Other non-operating income (expense), net of $29.0 in fiscal year 2017 primarily resulted from interest income on cash and time deposits, which are comprised primarily of proceeds from the sale of PMD.
Interest income was included in "Other income (expense), net" in 2016 and 2015.
Interest income in previous periods was not material.
Loss on Extinguishment of Debt On 30 September 2016, in anticipation of the spin-off of EMD, Versum issued $425.0 of notes to Air Products, who then exchanged these notes with certain financial institutions for $418.3 of Air Products’ outstanding commercial paper.
This noncash exchange, which was excluded from the consolidated statements of cash flows, resulted in a loss of $6.9 ($4.3 after-tax, or $.02 per share).
In September 2015, we made a payment of $146.6 to redeem 3,000,000 Unidades de Fomento (“UF”) Series E 6.30% Bonds due 22 January 2030 that had a carrying value of $130.0 and resulted in a net loss of $16.6 ($14.2 after-tax, or $.07 per share).
## Table 1 ##
(1) We acquired several companies during the periods presented and have included the financial results of these companies in our consolidated financial statements effective from the respective acquisition dates.
Refer to note 3 to our consolidated financial statements and related notes, which are included elsewhere in this Annual Report, for more information on these acquisitions.
(2) Our transaction and clearing fees are presented net of rebates paid to our customers.
We also report transaction-based expenses relating to Section 31 fees and payments made for routing services and to certain U. S.  equities liquidity providers.
For a discussion of these rebates, see Item 7 “- Management’s Discussion and Analysis of Financial Condition and Results of Operations - Segment Reporting - Trading and Clearing Segment” included elsewhere in this Annual Report.
IRON MOUNTAIN INCORPORATED NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued) DECEMBER 31, 2018 (In thousands, except share and per share data) 2.
Summary of Significant Accounting Policies (Continued) The costs associated with the initial movement of customer records into physical storage and certain commissions are considered costs to obtain or fulfill customer contracts (“Contract Fulfillment Costs”).
The following describes each of these Contract Fulfillment Costs recognized under ASU 2014-09: Intake Costs (and associated deferred revenue) Prior to the adoption of ASU 2014-09, intake costs incurred but not charged to a customer to transport records to our facilities (or Free Move Costs, as described in Note 2. i.
), which include labor and transportation costs, were capitalized and amortized as a component of depreciation and amortization in our Consolidated Statements of Operations.
The initial movement of customer records into physical storage must take place prior to initiation of the storage of records and is not considered a separate performance obligation and, therefore, the costs of the initial intake of customer records into physical storage (“Intake Costs”) represent a contract fulfillment cost for the storage of records as the earnings process does not commence until a customer’s records or other assets are in our possession.
Accordingly, upon the adoption of ASU 2014-09, all Intake Costs, regardless of whether or not the services associated with such initial moves are billed to the customer or are provided to the customer at no charge, will be deferred and amortized as a component of depreciation and amortization in our Consolidated Statements of Operations over three years, consistent with the transfer of the performance obligation to the customer to which the asset relates.
Similarly, in instances where such Intake Costs are billed to the customer, the associated revenue will be deferred and recognized over the same three-year period.
Commissions Prior to the adoption of ASU 2014-09, commissions we paid related to our long-term storage contracts were expensed as incurred.
Upon the adoption of ASU 2014-09, certain commission payments that are directly associated with the fulfillment of long-term storage contracts are capitalized and amortized as a component of depreciation and amortization in our Consolidated Statements of Operations over three years, consistent with the transfer of the performance obligation to the customer to which the asset relates.
Certain direct commission payments associated with contracts with a duration of one year or less are expensed as incurred under the practical expedient which allows an entity to expense as incurred an incremental cost of obtaining a contract if the amortization period of the asset that the entity otherwise would have recognized is one year or less.
The Contract Fulfillment Costs recorded as a result of the adoption of ASU 2014-09 as of January 1, 2018 and December 31, 2018 are as follows:
## Table 2 ##
Amortization expense associated with Contract Fulfillment Costs for the year ended December 31, 2018 is $10,380 and $13,838, respectively.

<table><tr><td></td><td>2017</td><td>2016</td><td>2015</td></tr><tr><td>Interest incurred</td><td>$139.6</td><td>$147.9</td><td>$151.9</td></tr><tr><td>Less: Capitalized interest</td><td>19.0</td><td>32.7</td><td>49.1</td></tr><tr><td>Interest Expense</td><td>$120.6</td><td>$115.2</td><td>$102.8</td></tr></table>
<table><tr><td rowspan="3"></td><td colspan="5">Year Ended December 31,</td></tr><tr><td>2017</td><td>2016</td><td>2015</td><td>2014</td><td>2013</td></tr><tr><td colspan="5">(In millions, except for per share data)</td></tr><tr><td>Consolidated Statement of Income Data<sup>-1</sup></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Revenues:</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Transaction and clearing, net<sup>-2</sup></td><td>$3,131</td><td>$3,384</td><td>$3,228</td><td>$3,144</td><td>$1,393</td></tr><tr><td>Data services</td><td>2,084</td><td>1,978</td><td>871</td><td>691</td><td>246</td></tr><tr><td>Listings</td><td>417</td><td>419</td><td>405</td><td>367</td><td>33</td></tr><tr><td>Other revenues</td><td>202</td><td>177</td><td>178</td><td>150</td><td>58</td></tr><tr><td>Total revenues</td><td>5,834</td><td>5,958</td><td>4,682</td><td>4,352</td><td>1,730</td></tr><tr><td>Transaction-based expenses<sup>-2</sup></td><td>1,205</td><td>1,459</td><td>1,344</td><td>1,260</td><td>132</td></tr><tr><td>Total revenues, less transaction-based expenses</td><td>4,629</td><td>4,499</td><td>3,338</td><td>3,092</td><td>1,598</td></tr><tr><td>Operating expenses:</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Compensation and benefits</td><td>937</td><td>945</td><td>611</td><td>592</td><td>302</td></tr><tr><td>Professional services</td><td>121</td><td>137</td><td>139</td><td>181</td><td>54</td></tr><tr><td>Acquisition-related transaction and integration costs<sup>-3</sup></td><td>36</td><td>80</td><td>88</td><td>129</td><td>143</td></tr><tr><td>Technology and communication</td><td>397</td><td>374</td><td>203</td><td>188</td><td>63</td></tr><tr><td>Rent and occupancy</td><td>69</td><td>70</td><td>57</td><td>78</td><td>39</td></tr><tr><td>Selling, general and administrative</td><td>155</td><td>116</td><td>116</td><td>143</td><td>51</td></tr><tr><td>Depreciation and amortization</td><td>535</td><td>610</td><td>374</td><td>333</td><td>156</td></tr><tr><td>Total operating expenses</td><td>2,250</td><td>2,332</td><td>1,588</td><td>1,644</td><td>808</td></tr><tr><td>Operating income</td><td>2,379</td><td>2,167</td><td>1,750</td><td>1,448</td><td>790</td></tr><tr><td>Other income (expense), net<sup>(4)</sup></td><td>138</td><td>-138</td><td>-97</td><td>-41</td><td>-286</td></tr><tr><td>Income from continuing operations before income tax expense (benefit)</td><td>2,517</td><td>2,029</td><td>1,653</td><td>1,407</td><td>504</td></tr><tr><td>Income tax expense (benefit)<sup>(5)</sup></td><td>-25</td><td>580</td><td>358</td><td>402</td><td>184</td></tr><tr><td>Income from continuing operations</td><td>2,542</td><td>1,449</td><td>1,295</td><td>1,005</td><td>320</td></tr><tr><td>Income (loss) from discontinued operations, net of tax<sup>(6)</sup></td><td>—</td><td>—</td><td>—</td><td>11</td><td>-50</td></tr><tr><td>Net income</td><td>$2,542</td><td>$1,449</td><td>$1,295</td><td>$1,016</td><td>$270</td></tr><tr><td>Net income attributable to non-controlling interest</td><td>-28</td><td>-27</td><td>-21</td><td>-35</td><td>-16</td></tr><tr><td>Net income attributable to ICE<sup>-7</sup></td><td>$2,514</td><td>$1,422</td><td>$1,274</td><td>$981</td><td>$254</td></tr><tr><td>Basic earnings (loss) per share attributable to ICE common shareholders:</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Continuing operations<sup>-7</sup></td><td>$4.27</td><td>$2.39</td><td>$2.29</td><td>$1.70</td><td>$0.78</td></tr><tr><td>Discontinued operations<sup>-6</sup></td><td>—</td><td>—</td><td>—</td><td>0.02</td><td>-0.13</td></tr><tr><td>Basic earnings per share</td><td>$4.27</td><td>$2.39</td><td>$2.29</td><td>$1.72</td><td>$0.65</td></tr><tr><td>Basic weighted average common shares outstanding<sup>-8</sup></td><td>589</td><td>595</td><td>556</td><td>570</td><td>392</td></tr><tr><td>Diluted earnings (loss) per share attributable to ICE common shareholders:</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Continuing operations<sup>-7</sup></td><td>$4.23</td><td>$2.37</td><td>$2.28</td><td>$1.69</td><td>$0.77</td></tr><tr><td>Discontinued operations<sup>-6</sup></td><td>—</td><td>—</td><td>—</td><td>0.02</td><td>-0.13</td></tr><tr><td>Diluted earnings per share</td><td>$4.23</td><td>$2.37</td><td>$2.28</td><td>$1.71</td><td>$0.64</td></tr><tr><td>Diluted weighted average common shares outstanding<sup>-8</sup></td><td>594</td><td>599</td><td>559</td><td>573</td><td>396</td></tr><tr><td>Dividend per share</td><td>$0.80</td><td>$0.68</td><td>$0.58</td><td>$0.52</td><td>$0.13</td></tr></table>
<table><tr><td></td><td></td><td colspan="3">January 1, 2018 (Date of Adoption ofASU 2014-09)</td><td colspan="3">December 31, 2018</td></tr><tr><td>Description</td><td>Location in Balance Sheet</td><td>Gross Carrying Amount</td><td>Accumulated Amortization</td><td>Net Carrying Amount</td><td>Gross Carrying Amount</td><td>Accumulated Amortization</td><td>Net Carrying Amount</td></tr><tr><td>Intake Costs asset</td><td>Other (within Other Assets, Net)</td><td>$31,604</td><td>$-14,954</td><td>$16,650</td><td>$39,748</td><td>$-24,504</td><td>15,244</td></tr><tr><td>Commissions asset</td><td>Other (within Other Assets, Net)</td><td>42,072</td><td>-21,173</td><td>20,899</td><td>58,424</td><td>-34,637</td><td>23,787</td></tr></table>

Question: what is the decrease observed in the capitalized interest during 2015 and 2016?