CDW CORPORATION AND SUBSIDIARIES NOTES TO CONSOLIDATED FINANCIAL STATEMENTS 2013 denominator was impacted by the common shares issued during both the IPO and the underwriters’ exercise in full of the overallotment option granted to them in connection with the IPO.
Because such common shares were issued on July 2, 2013 and July 31, 2013, respectively, they are only partially reflected in the 2013 denominator.
Such shares will be fully reflected in the 2014 denominator.
See Note 9 for additional discussion of the IPO.
The dilutive effect of outstanding restricted stock, restricted stock units, stock options and MPK Plan units is reflected in the denominator for diluted earnings per share using the treasury stock method.
The following is a reconciliation of basic shares to diluted shares:
## Table 0 ##
For the years ended December 31, 2013, 2012 and 2011, diluted earnings per share excludes the impact of 0.0 million, 0.0 million, and 4.3 million potential common shares, respectively, as their inclusion would have had an anti-dilutive effect.12.
Deferred Compensation Plan On March 10, 2010, in connection with the Company’s purchase of $28.5 million principal amount of its outstanding senior subordinated debt, the Company established the Restricted Debt Unit Plan (the “RDU Plan”), an unfunded nonqualified deferred compensation plan.
The total number of RDUs that can be granted under the RDU Plan is 28,500.
At December 31, 2013, 28,500 RDUs were outstanding.
RDUs that are outstanding vest daily on a pro rata basis over the three-year period from January 1, 2012 (or, if later, the date of hire or the date of a subsequent RDU grant) through December 31, 2014.
Participants have no rights to the underlying debt.
The total amount of compensation available to be paid under the RDU Plan was initially to be based on two components, a principal component and an interest component.
The principal component credits the RDU Plan with a notional amount equal to the $28.5 million face value of the Senior Subordinated Notes (the “Debt Pool”), together with certain redemption premium equivalents as noted below.
The interest component credits the RDU Plan with amounts equal to the interest that would have been earned on the Debt Pool from March 10, 2010 through maturity on October 12, 2017, except as discussed below.
Interest amounts for 2010 and 2011 were deferred until 2012, and thereafter, interest amounts were paid to participants semi-annually on the interest payment due dates.
Payments totaling $1.7 million and $1.3 million were made to participants under the RDU Plan in April and October 2013, respectively, in connection with the semi-annual interest payments due.
The Company used a portion of the IPO proceeds together with incremental borrowings to redeem $324.0 million of the total Senior Subordinated Notes outstanding on August 1, 2013.
In connection with the IPO and the partial redemption of the Senior Subordinated Notes, the Company amended the RDU Plan to increase the retentive value of the plan.
In accordance with the original terms of the RDU Plan, the principal component of the RDUs converted to a cash-denominated pool upon the redemption of the Senior Subordinated Notes.
In addition, the Company added $1.4 million to the principal component in the year ended December 31, 2013 as redemption premium equivalents in accordance with the terms of the RDU plan.
Under the terms of the amended RDU Plan, upon the partial redemption of outstanding Senior Subordinated Notes, the RDUs ceased to accrue the proportionate related interest component credits.
The
## Table 1 ##
Use of Proceeds from Registered Securities On July 2, 2013, the Company completed an IPO of its common stock in which it issued and sold 23,250,000 shares of common stock.
On July 31, 2013, the Company completed the sale of an additional 3,487,500 shares of common stock to the underwriters of the IPO pursuant to the underwriters’ July 26, 2013 exercise in full of the overallotment option granted to them in connection with the IPO.
Such shares were registered under the Securities Act of 1933, as amended, pursuant to the Company’s Registration Statement on Form S-1 (File 333-187472), which was declared effective by the SEC on June 26, 2013.
The shares of common stock are listed on the NASDAQ Global Select Market under the symbol “CDW.
” The Company’s shares of common stock were sold to the underwriters at a price of $17.00 per share in the IPO and upon the exercise of the overallotment option, which together, generated aggregate net proceeds of $424.7 million to the Company after deducting $29.8 million in underwriting discounts, expenses and transaction costs.
Using a portion of the net proceeds from the IPO (exclusive of proceeds from the exercise of the overallotment option), the Company paid a $24.4 million termination fee to affiliates of Madison Dearborn Partners, LLC and Providence Equity Partners, L. L. C.  in connection with the termination of the management services agreement with such entities that was effective upon completion of the IPO, redeemed $175.0 million aggregate principal amount of senior secured notes due 2018, and redeemed $146.0 million aggregate principal amount of senior subordinated notes due 2017.
The redemption price of the senior secured notes due 2018 was 108.0% of the principal amount redeemed, plus accrued and unpaid interest to the date of redemption.
The Company used cash on hand to pay such accrued and unpaid interest.
The redemption price of the senior subordinated notes due 2017 was 106.268% of the principal amount redeemed, plus accrued and unpaid interest to the date of redemption.
The Company used cash on hand to pay such accrued and unpaid interest.
On October 18, 2013, proceeds from the overallotment option exercise of $56.0 million and cash on hand were used to redeem $155.0 million aggregate principal amount of senior subordinated notes due 2017.
The redemption price of the senior subordinated notes due 2017 was 104.178% of the principal amount redeemed, plus accrued and unpaid interest to the date of redemption.
The Company used cash on hand to pay such redemption premium and accrued and unpaid interest.
J. P.  Morgan Securities LLC, Barclays Capital Inc.  and Goldman, Sachs & Co.  acted as joint book-running managers of the IPO and as representatives of the underwriters.
Deutsche Bank Securities Inc.  and Morgan Stanley & Co.  LLC acted as additional book-running managers in the IPO.
Robert W.  Baird & Co.
Incorporated, Raymond James & Associates, Inc. , William Blair & Company, L. L. C. , Needham & Company, LLC, Stifel, Nicolaus & Company, Incorporated, Loop Capital Markets LLC and The Williams Capital Group, L. P.  acted as managing underwriters in the IPO.
(2) For purposes of calculating the ratio of earnings to fixed charges, earnings consist of earnings before income taxes minus income from equity investees plus fixed charges.
Fixed charges consist of interest expense and the portion of rental expense we believe is representative of the interest component of rental expense.
(a) For the years ended December 31, 2010 and 2009, earnings available for fixed charges were inadequate to cover fixed charges by $37.0 million and $461.2 million, respectively.
(3) EBITDA is defined as consolidated net income (loss) before interest expense, income tax expense (benefit), depreciation, and amortization.
Adjusted EBITDA, which is a measure defined in our credit agreements, is calculated by adjusting EBITDA for certain items of income and expense including (but not limited to) the following: (a) non-cash equity-based compensation; (b) goodwill impairment charges; (c) sponsor fees; (d) certain consulting fees; (e) debt-related legal and accounting costs; (f) equity investment income and losses; (g) certain severance and retention costs; (h) gains and losses from the early extinguishment of debt; (i) gains and losses from asset dispositions outside the ordinary course of business; and (j) non-recurring, extraordinary or unusual gains or losses or expenses.
We have included a reconciliation of EBITDA and Adjusted EBITDA in the table below.
Both EBITDA and Adjusted EBITDA are considered non-GAAP financial measures.
Generally, a non-GAAP financial measure is a numerical measure of a company’s performance, financial position or cash flows that either excludes or includes amounts that are not normally included or excluded in the most directly comparable measure calculated and presented in accordance with GAAP.
Non-GAAP measures used by the Company may differ from similar measures used by other companies, even when similar terms are used to identify such measures.
We believe that EBITDA and Adjusted EBITDA provide helpful information with respect to our operating performance and cash flows including our ability to meet our future debt service, capital expenditures and working capital requirements.
Adjusted EBITDA also provides helpful information as it is the primary measure used in certain financial covenants contained in our credit agreements.
The following unaudited table sets forth reconciliations of net income (loss) to EBITDA and EBITDA to Adjusted EBITDA for the periods presented:
## Table 2 ##
(i) Relates to unusual, non-recurring litigation matters.
(ii) Includes certain retention costs and equity investment income, certain severance costs in 2009 and a gain related to the sale of the Informacast software and equipment in 2009.
The gross profit margin may fluctuate based on various factors, including vendor incentive and inventory price protection programs, cooperative advertising funds classified as a reduction of cost of sales, product mix, net service contract revenue, commission revenue, pricing strategies, market conditions and other factors, any of which could result in changes in gross profit margins.
Selling and administrative expenses Selling and administrative expenses increased $91.3 million, or 8.9%, to $1,120.9 million in 2013, compared to $1,029.5 million in 2012.
As a percentage of total net sales, selling and administrative expenses increased 20 basis points to 10.4% in 2013, up from 10.2% in 2012.
Sales payroll, including sales commissions and other variable compensation costs, increased $28.9 million, or 6.4%, between years, consistent with higher sales and gross profit.
Additionally, selling and administrative expenses for 2013 included IPO- and secondary-offering related expenses of $75.0 million, as follows: ?
Pre-tax charges of $36.7 million related to the acceleration of the expense recognition for certain equity awards and $4.0 million for the related employer payroll taxes.
See Note 10 of the accompanying audited consolidated financial statements for additional discussion of the impact of the IPO on our equity awards.  ?
A pre-tax charge of $24.4 million related to the payment of a termination fee to affiliates of the Sponsors in connection with the termination of the management services agreement with such entities.  ?
A pre-tax charge of $7.5 million related to compensation expense in connection with the Restricted Debt Unit Plan.
See Note 12 of the accompanying audited consolidated financial statements for additional discussion of this charge.  ?
Other IPO- and secondary-offering related expenses of $2.4 million.
We did not record any IPO- or secondary-offering related expenses during 2012.
Partially offsetting these increases in 2013 was the favorable resolution of a class action legal proceeding in which we were a claimant, which reduced selling and administrative expenses by $10.4 million in 2013 compared to 2012.
Total coworker count increased by 163 coworkers, from 6,804 at December 31, 2012, to 6,967 at December 31, 2013.
Advertising expense Advertising expense increased $1.3 million, or 0.9%, to $130.8 million in 2013, compared to $129.5 million in 2012.
As a percentage of net sales, advertising expense was 1.2% in 2013, compared to 1.3% in 2012.
The dollar increase in advertising expense was due to a continued focus on advertising our solutions and products, which reinforces our reputation as a leading IT solutions provider.
Income from operations The following table presents income from operations by segment, in dollars and as a percentage of net sales, and the year-over-year percentage change in income from operations for the years ended December 31, 2013 and 2012:

Tables referenced above, in order (Table 0 first):
<table><tr><td></td><td>Years Ended December 31,</td></tr><tr><td>(in millions)</td><td>2013</td><td>2012</td><td>2011</td></tr><tr><td>Weighted-average shares - basic</td><td>156.6</td><td>145.1</td><td>144.8</td></tr><tr><td>Effect of dilutive securities</td><td>2.1</td><td>0.7</td><td>0.1</td></tr><tr><td>Weighted-average shares - diluted</td><td>158.7</td><td>145.8</td><td>144.9</td></tr></table>
<table><tr><td></td><td>June 27, 2013</td><td>December 31, 2013</td></tr><tr><td>CDW Corp</td><td>$100</td><td>$138</td></tr><tr><td>S&P MidCap 400 index</td><td>100</td><td>118</td></tr><tr><td>CDW Peers</td><td>100</td><td>113</td></tr></table>
<table><tr><td></td><td colspan="5">Years Ended December 31,</td></tr><tr><td>(in millions)</td><td>2013</td><td>2012</td><td>2011</td><td>2010</td><td>2009</td></tr><tr><td>Net income (loss)</td><td>$132.8</td><td>$119.0</td><td>$17.1</td><td>$-29.2</td><td>$-373.4</td></tr><tr><td>Depreciation and amortization</td><td>208.2</td><td>210.2</td><td>204.9</td><td>209.4</td><td>218.2</td></tr><tr><td>Income tax expense (benefit)</td><td>62.7</td><td>67.1</td><td>11.2</td><td>-7.8</td><td>-87.8</td></tr><tr><td>Interest expense, net</td><td>250.1</td><td>307.4</td><td>324.2</td><td>391.9</td><td>431.7</td></tr><tr><td>EBITDA</td><td>653.8</td><td>703.7</td><td>557.4</td><td>564.3</td><td>188.7</td></tr><tr><td>Non-cash equity-based compensation</td><td>8.6</td><td>22.1</td><td>19.5</td><td>11.5</td><td>15.9</td></tr><tr><td>Sponsor fees</td><td>2.5</td><td>5.0</td><td>5.0</td><td>5.0</td><td>5.0</td></tr><tr><td>Consulting and debt-related professional fees</td><td>0.1</td><td>0.6</td><td>5.1</td><td>15.1</td><td>14.1</td></tr><tr><td>Goodwill impairment</td><td>—</td><td>—</td><td>—</td><td>—</td><td>241.8</td></tr><tr><td>Net loss (gain) on extinguishments of long-term debt</td><td>64.0</td><td>17.2</td><td>118.9</td><td>-2.0</td><td>—</td></tr><tr><td>Litigation, net<sup>(i)</sup></td><td>-4.1</td><td>4.3</td><td>—</td><td>—</td><td>—</td></tr><tr><td>IPO- and secondary-offering related expenses</td><td>75.0</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Other adjustments<sup>(ii)</sup></td><td>8.6</td><td>13.7</td><td>11.4</td><td>7.9</td><td>-0.1</td></tr><tr><td>Adjusted EBITDA</td><td>$808.5</td><td>$766.6</td><td>$717.3</td><td>$601.8</td><td>$465.4</td></tr></table>

Question: under the rdu program in 2013 , what was the average of the two semi-annual interest payments , in millions?
Answer: 1.5
Reasoning program: add(1.7,1.3), divide(#0,const_2)