4.  BUSINESS RESTRUCTURING AND COST REDUCTION PLANS We recorded charges in 2013 and 2012 for business restructuring and cost reduction plans.
These charges are reflected on the consolidated income statements as “Business Restructuring and Cost Reduction Plans.
” The charges for these plans have been excluded from segment operating income.2013 Plan During the fourth quarter of 2013, we recorded an expense of $231.6 ($157.9 after-tax, or $.74 per share) reflecting actions to better align our cost structure with current market conditions.
These charges include $100.4 for asset actions and $58.5 for the final settlement of a long-term take-or-pay silane contract primarily impacting the Electronics business due to continued weakness in the photovoltaic (PV) and light-emitting diode (LED) markets.
In addition, $71.9 was recorded for severance, benefits, and other contractual obligations associated with the elimination of approximately 700 positions and executive changes.
These charges primarily impact our Merchant Gases businesses and corporate functions.
The actions are in response to weaker than expected business conditions in Europe and Asia, reorganization of our operations and functional areas, and previously announced senior executive changes.
The planned actions are expected to be completed by the end of fiscal year 2014.
The 2013 charges relate to the businesses at the segment level as follows: $61.0 in Merchant Gases, $28.6 in Tonnage Gases, $141.0 in Electronics and Performance Materials, and $1.0 in Equipment and Energy.
The following table summarizes the carrying amount of the accrual for the 2013 plan at 30 September 2013:
## Table 0 ##
2012 Plans In 2012, we recorded an expense of $327.4 ($222.4 after-tax, or $1.03 per share) for business restructuring and cost reduction plans in our Polyurethane Intermediates (PUI), Electronics, and European Merchant businesses.
During the second quarter of 2012, we recorded an expense of $86.8 ($60.6 after-tax, or $.28 per share) for actions to remove stranded costs resulting from our decision to exit the Homecare business, the reorganization of the Merchant business, and actions to right-size our European cost structure in light of the challenging economic outlook.
The charge related to the businesses at the segment level as follows: $77.3 in Merchant Gases, $3.8 in Tonnage Gases, and $5.7 in Electronics and Performance Materials.
As of 30 September 2013, the planned actions were completed.
During the fourth quarter of 2012, we took actions to exit the PUI business to improve costs, resulting in a net expense of $54.6 ($34.8 after-tax, or $.16 per share).
We sold certain assets and the rights to a supply contract for $32.7 in cash at closing.
In connection with these actions, we recognized an expense of $26.6, for the net book value of assets sold and those committed to be disposed of other than by sale.
The remaining charge was primarily related to contract terminations and an environmental liability.
Our PUI production facility in Pasadena, Texas is currently being dismantled, with completion expected in fiscal year 2014.
The costs to dismantle are expensed as incurred and reflected in continuing operations in the Tonnage Gases business segment.
During the fourth quarter of 2012, we completed an assessment of our position in the PV market, resulting in $186.0 of expense ($127.0 after-tax, or $.59 per share) primarily related to the Electronics and Performance Materials segment.
Air Products supplies the PV market with both bulk and on-site supply of gases, including silane.
The PV market has not developed as expected, and as a result, the market capacity to produce silane is expected to exceed demand for the foreseeable future.
Included in the charge was an accrual of $93.5 for an offer that we made to terminate a long-term take-or-pay contract to purchase silane.
A final settlement was reached with the supplier in the fourth quarter of 2013.
Note About Our MAU Adjustment In the third quarter of 2017, we discovered that since the fourth quarter of 2014 we had included users of certain third-party applications as Twitter MAUs that should not have been considered MAUs.
These third-party applications used Digits, a software development kit of our now-divested Fabric platform, that allowed third-party applications to send authentication messages via SMS through our systems, which did not relate to activity on the Twitter platform.
The table below presents the impact for the periods beginning in the fourth quarter of 2016.
Due to our data retention policies, we do not have data to reconcile periods prior to the fourth quarter of 2016, but our estimates suggest the prior period adjustments are smaller than those in the fourth quarter of 2016.
## Table 1 ##
(1) The difference between Adjusted MAU and Previously Reported MAU does not correspond to the amount of the Adjustment due to rounding.
Changes in Daily Active Users/Daily Active Usage (DAU).
We define daily active users or daily active usage as Twitter users who logged in or were otherwise authenticated and accessed Twitter through our website, mobile website or mobile applications on any given day.
Average DAU for a period represents the number of DAUs on each day of such period divided by the number of days for such period.
Changes in DAU are a measure of changes in the size of our daily logged in or otherwise authenticated active user base.
To calculate the year-over-year change in DAUs, we subtract the average DAU for the three months ended in the previous year from the average DAU for the same three months ended in the current year and divide the result by the average DAU for the three months ended in the previous year.
Prior to reporting results for the third quarter of 2016, we had discussed DAUs and the ratio of MAUs to DAUs.
In those instances, for comparability and consistency with MAUs, DAUs also included users who accessed Twitter through our desktop applications and third-party properties.
For additional information on how we calculate changes in DAUs and factors that can affect this metric, see the section titled “Note Regarding Key Metrics.
” Reported DAU metrics were not impacted by the MAU adjustment discussed above as DAU do not include users from third-party applications.
DAU grew faster than MAU in the fourth quarter of 2017 as we continued to benefit from organic growth, product and marketing investments made in this quarter and in prior periods.
Changes in Ad Engagements and Cost per Ad Engagement.
We define an ad engagement as a user interaction with one of our pay-for-performance advertising products.
Ad engagements with our advertising products are based on a user completing an objective set out by an advertiser such as expanding, Retweeting, liking or replying to a Promoted Tweet, viewing an embedded video, downloading or engaging with a promoted mobile application, clicking on a website link, signing up for marketing emails from advertisers, following the account that tweets a Promoted Tweet, or completing a transaction on an external website.
We believe changes in ad engagements is one way to measure user engagement with our advertising products.
We believe changes in cost per ad engagement is one way to measure demand.
(1) In the fourth quarter of 2016, we incurred $101.2 million of restructuring charges.
Costs and expenses include stock-based compensation expense as follows:
## Table 2 ##
(2) In the second and third quarter of 2017, we incurred $55.0 million and $7.4 million of other-than-temporary impairment charges on a cost-method investment, respectively.
(3) The following table presents a reconciliation of net income (loss) to Adjusted EBITDA for each of the periods indicated:
## Table 3 ##
(4) The following table presents a reconciliation of net income (loss) to non-GAAP net income for each of the periods indicated:
## Table 4 ##
The Notes consisted of the following (in thousands):

<table><tr><td></td><td>Severance and Other Benefits</td><td>Asset Actions</td><td>Contract Actions/ Other</td><td>Total</td></tr><tr><td>2013 Charge</td><td>$71.9</td><td>$100.4</td><td>$59.3</td><td>$231.6</td></tr><tr><td>Amount reflected in pension liability</td><td>-6.9</td><td>—</td><td>—</td><td>-6.9</td></tr><tr><td>Noncash expenses</td><td>—</td><td>-100.4</td><td>—</td><td>-100.4</td></tr><tr><td>Cash expenditures</td><td>-3.0</td><td>—</td><td>-58.5</td><td>-61.5</td></tr><tr><td>Currency translation adjustment</td><td>.4</td><td>—</td><td>—</td><td>.4</td></tr><tr><td>Accrued balance</td><td>$62.4</td><td>$—</td><td>$.8</td><td>$63.2</td></tr></table>
<table><tr><td></td><td colspan="3">Three Months Ended December 31, 2016</td><td colspan="3">Three Months Ended March 31, 2017</td><td colspan="3">Three Months Ended June 30, 2017</td></tr><tr><td></td><td>United States</td><td>International</td><td>Worldwide</td><td>United States</td><td>International (in millions)</td><td>Worldwide</td><td>United States</td><td>International</td><td>Worldwide</td></tr><tr><td>Previously Reported MAU</td><td>67</td><td>252</td><td>319</td><td>70</td><td>259</td><td>328</td><td>68</td><td>260</td><td>328</td></tr><tr><td>Adjustment<sup>-1</sup></td><td>—</td><td>-1</td><td>-1</td><td>-1</td><td>-1</td><td>-2</td><td>—</td><td>-2</td><td>-2</td></tr><tr><td>Adjusted MAU</td><td>67</td><td>251</td><td>318</td><td>69</td><td>257</td><td>327</td><td>68</td><td>258</td><td>326</td></tr><tr><td colspan="10">-1 The difference between Adjusted MAU and Previously Reported MAU does not correspond to the amount of the Adjustment due to rounding.</td></tr></table>
<table><tr><td></td><td colspan="8">Three Months Ended</td></tr><tr><td></td><td>Dec. 31, 2017</td><td>Sep. 30, 2017</td><td>Jun. 30, 2017</td><td>Mar. 31, 2017</td><td>Dec. 31, 2016</td><td>Sep. 30, 2016</td><td>Jun. 30, 2016</td><td>Mar. 31, 2016</td></tr><tr><td></td><td colspan="8">(Unaudited, in thousands)</td></tr><tr><td>Cost of revenue</td><td>$6,019</td><td>$5,625</td><td>$6,253</td><td>$5,952</td><td>$6,511</td><td>$7,165</td><td>$7,858</td><td>$7,968</td></tr><tr><td>Research and development</td><td>55,648</td><td>57,174</td><td>63,625</td><td>64,386</td><td>81,840</td><td>87,163</td><td>90,916</td><td>75,579</td></tr><tr><td>Sales and marketing</td><td>25,919</td><td>22,433</td><td>20,694</td><td>25,089</td><td>27,751</td><td>41,227</td><td>45,856</td><td>46,101</td></tr><tr><td>General and administrative</td><td>14,868</td><td>15,727</td><td>22,824</td><td>21,570</td><td>21,993</td><td>22,972</td><td>23,065</td><td>21,268</td></tr><tr><td>Total stock-based compensation expense</td><td>$102,454</td><td>$100,959</td><td>$113,396</td><td>$116,997</td><td>$138,095</td><td>$158,527</td><td>$167,695</td><td>$150,916</td></tr></table>
<table><tr><td></td><td colspan="8">Three Months Ended</td></tr><tr><td></td><td>Dec. 31, 2017</td><td>Sep. 30, 2017</td><td>Jun. 30, 2017</td><td>Mar. 31, 2017</td><td>Dec. 31, 2016</td><td>Sep. 30, 2016</td><td>Jun. 30, 2016</td><td>Mar. 31, 2016</td></tr><tr><td></td><td colspan="8">(Unaudited, in thousands)</td></tr><tr><td>Reconciliation of Net Income (Loss) to Adjusted EBITDA:</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Net income (loss)</td><td>$91,079</td><td>$-21,095</td><td>$-116,488</td><td>$-61,559</td><td>$-167,054</td><td>$-102,871</td><td>$-107,217</td><td>$-79,731</td></tr><tr><td>Stock-based compensation expense</td><td>102,454</td><td>100,959</td><td>113,396</td><td>116,997</td><td>138,095</td><td>158,527</td><td>167,695</td><td>150,916</td></tr><tr><td>Depreciation and amortization expense</td><td>92,520</td><td>97,492</td><td>103,063</td><td>102,792</td><td>119,390</td><td>100,878</td><td>93,283</td><td>88,621</td></tr><tr><td>Interest and other expense, net</td><td>16,545</td><td>24,810</td><td>74,716</td><td>18,087</td><td>18,619</td><td>18,220</td><td>18,200</td><td>18,587</td></tr><tr><td>Provision for income taxes</td><td>2,474</td><td>3,564</td><td>3,413</td><td>3,194</td><td>4,808</td><td>6,562</td><td>2,641</td><td>2,028</td></tr><tr><td>Restructuring charges and one-time nonrecurring gain</td><td>3,102</td><td>1,269</td><td>-226</td><td>-9,572</td><td>101,249</td><td>—</td><td>—</td><td>47</td></tr><tr><td>Adjusted EBITDA</td><td>$308,174</td><td>$206,999</td><td>$177,874</td><td>$169,939</td><td>$215,107</td><td>$181,316</td><td>$174,602</td><td>$180,468</td></tr></table>
<table><tr><td></td><td colspan="8">Three Months Ended</td></tr><tr><td></td><td>Dec. 31, 2017</td><td>Sep. 30, 2017</td><td>Jun. 30, 2017</td><td>Mar. 31, 2017</td><td>Dec. 31, 2016</td><td>Sep. 30, 2016</td><td>Jun. 30, 2016</td><td>Mar. 31, 2016</td></tr><tr><td></td><td colspan="8">(Unaudited, in thousands)</td></tr><tr><td>Reconciliation of Net Income (Loss) to Non-GAAP Net Income:</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Net income (loss)</td><td>$91,079</td><td>$-21,095</td><td>$-116,488</td><td>$-61,559</td><td>$-167,054</td><td>$-102,871</td><td>$-107,217</td><td>$-79,731</td></tr><tr><td>Exclude: Provision for income taxes</td><td>2,474</td><td>3,564</td><td>3,413</td><td>3,194</td><td>4,808</td><td>6,562</td><td>2,641</td><td>2,028</td></tr><tr><td>Income (loss) before income taxes</td><td>93,553</td><td>-17,531</td><td>-113,075</td><td>-58,365</td><td>-162,246</td><td>-96,309</td><td>-104,576</td><td>-77,703</td></tr><tr><td>Stock-based compensation expense</td><td>102,454</td><td>100,959</td><td>113,396</td><td>116,997</td><td>138,095</td><td>158,527</td><td>167,695</td><td>150,916</td></tr><tr><td>Amortization of acquired intangible assets</td><td>4,929</td><td>11,077</td><td>14,340</td><td>16,191</td><td>27,220</td><td>16,572</td><td>12,816</td><td>12,730</td></tr><tr><td>Non-cash interest expense related to convertible notes</td><td>20,417</td><td>20,355</td><td>20,041</td><td>19,248</td><td>19,070</td><td>18,650</td><td>18,570</td><td>18,370</td></tr><tr><td>Impairment of investments in privately-held companies</td><td>—</td><td>7,439</td><td>55,000</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Restructuring charges and one-time nonrecurring gain</td><td>3,102</td><td>1,269</td><td>-226</td><td>-9,572</td><td>101,249</td><td>—</td><td>—</td><td>47</td></tr><tr><td>Non-GAAP income before income taxes</td><td>224,455</td><td>123,568</td><td>89,476</td><td>84,499</td><td>123,388</td><td>97,440</td><td>94,505</td><td>104,360</td></tr><tr><td>Non-GAAP provision for income taxes</td><td>83,048</td><td>45,720</td><td>33,106</td><td>31,265</td><td>45,654</td><td>36,053</td><td>34,967</td><td>38,613</td></tr><tr><td>Non-GAAP net income</td><td>$141,407</td><td>$77,848</td><td>$56,370</td><td>$53,234</td><td>$77,734</td><td>$61,387</td><td>$59,538</td><td>$65,747</td></tr></table>

Question: Does Depreciation and amortization expense keeps increasing each year between Jun. 30,2016 and Jun. 30, 2017?
Answer: yes