Sources of Revenue Our revenues are primarily derived from the planning and execution of multi-channel advertising, marketing and communications programs around the world.
Our revenues are directly dependent upon the advertising, marketing and corporate communications requirements of our existing clients and our ability to win new clients.
Most of our client contracts are individually negotiated and, accordingly, the terms of client engagements and the bases on which we earn commissions and fees vary significantly.
As is customary in the industry, our contracts generally provide for termination by either party on relatively short notice, usually 90 days.
Revenues for the creation, planning and placement of advertising are determined primarily on a negotiated fee basis and, to a lesser extent, on a commission basis.
Fees are usually calculated to reflect hourly rates plus proportional overhead and a mark-up.
Many clients include an incentive compensation component in their total compensation package.
This provides added revenue based on achieving mutually agreed-upon qualitative or quantitative metrics within specified time periods.
Commissions are earned based on services provided and are usually derived from a percentage or fee over the total cost to complete the assignment.
Commissions can also be derived when clients pay us the gross rate billed by media and we pay for media at a lower net rate; the difference is the commission that we earn, which we either retain in full or share with the client depending on the nature of the applicable services agreement.
We also generate revenue in negotiated fees from our public relations, sales promotion, event marketing, sports and entertainment marketing and corporate and brand identity services.
In most of our businesses, our agencies enter into commitments to pay production and media costs on behalf of clients.
To the extent possible, we pay production and media charges after we have received funds from our clients.
Generally, we act as the client’s agent rather than the primary obligor.
In some instances we agree with the provider that we will only be liable to pay the production and media costs after the client has paid us for the charges.
Our revenue is typically lowest in the first quarter and highest in the fourth quarter.
This reflects the seasonal spending of our clients, incentives earned at year end on various contracts and project work completed that is typically recognized during the fourth quarter.
Fee revenue recognized on a completed contract basis also contributes to the higher seasonal revenues experienced in the fourth quarter because the majority of our contracts end at December 31.
## Table 0 ##
See Note 1 to the Consolidated Financial Statements for further information on our revenue recognition accounting policies.
Clients Our large and diverse client base includes many of the most recognizable companies and brands throughout the world.
Our holding company structure allows us to maintain a diversified client base across and within a full range of industry sectors.
In the aggregate, our top ten clients based on revenue accounted for approximately 21% of revenue in 2013 and 2012.
Our largest client accounted for approximately 5% of revenue for 2013 and 2012.
Based on revenue for the year ended December 31, 2013, our five largest clients (in alphabetical order) were General Motors, Johnson & Johnson, L’Oréal, Microsoft and Unilever.
We represent several different brands or divisions of each of these clients in a number of geographic markets, as well as provide services across multiple advertising and marketing disciplines, in each case through more than one of our agency brands.
Representation of a client rarely means that we handle advertising for all brands or product lines of the client in all geographical locations.
Any client may transfer its business from one of our agencies to another one of our agencies or to a competing agency, and a client may reduce its marketing budget at any time.
Management’s Discussion and Analysis of Financial Condition and Results of Operations – (continued) (Amounts in Millions, Except Per Share Amounts) Corporate and other expenses decreased slightly during 2012 by $4.7 to $137.3 compared to 2011, primarily due to lower office and general expenses, partially offset by an increase in temporary help to support our information-technology system-upgrade initiatives.
LIQUIDITY AND CAPITAL RESOURCES CASH FLOW OVERVIEW The following tables summarize key financial data relating to our liquidity, capital resources and uses of capital.
## Table 1 ##
1 Reflects net income adjusted primarily for depreciation and amortization of fixed assets and intangible assets, amortization of restricted stock and other non-cash compensation, non-cash loss related to early extinguishment of debt, and deferred income taxes.2 Reflects changes in accounts receivable, expenditures billable to clients, other current assets, accounts payable and accrued liabilities.
Operating Activities Net cash provided by operating activities during 2013 was $592.9, which was an increase of $235.7 as compared to 2012, primarily as a result of an improvement in working capital usage of $283.6, offset by a decrease in net income.
Due to the seasonality of our business, we typically generate cash from working capital in the second half of a year and use cash from working capital in the first half of a year, with the largest impacts in the first and fourth quarters.
The improvement in working capital in 2013 was impacted by our media businesses and an ongoing focus on working capital management at our agencies.
Net cash provided by operating activities during 2012 was $357.2, which was an increase of $83.7 as compared to 2011, primarily as a result of a decrease in working capital usage of $66.2.
The net working capital usage in 2012 was primarily impacted by our media businesses.
The timing of media buying on behalf of our clients affects our working capital and operating cash flow.
In most of our businesses, our agencies enter into commitments to pay production and media costs on behalf of clients.
To the extent possible we pay production and media charges after we have received funds from our clients.
The amounts involved substantially exceed our revenues, and primarily affect the level of accounts receivable, expenditures billable to clients, accounts payable and accrued liabilities.
Our assets include both cash received and accounts receivable from clients for these pass-through arrangements, while our liabilities include amounts owed on behalf of clients to media and production suppliers.
Our accrued liabilities are also affected by the timing of certain other payments.
For example, while annual cash incentive awards are accrued throughout the year, they are generally paid during the first quarter of the subsequent year.
Investing Activities Net cash used in investing activities during 2013 primarily relates to payments for capital expenditures and acquisitions.
Capital expenditures of $173.0 relate primarily to computer hardware and software and leasehold improvements.
We made payments of $61.5 related to acquisitions completed during 2013.
Management’s Discussion and Analysis of Financial Condition and Results of Operations – (continued) (Amounts in Millions, Except Per Share Amounts) Net cash used in investing activities during 2012 primarily related to payments for capital expenditures and acquisitions, partially offset by the net proceeds of $94.8 received from the sale of our remaining holdings in Facebook.
Capital expenditures of $169.2 primarily related to computer hardware and software, and leasehold improvements.
Capital expenditures increased in 2012 compared to the prior year, primarily due to an increase in leasehold improvements made during the year.
Payments for acquisitions of $145.5 primarily related to payments for new acquisitions.
Financing Activities Net cash used in financing activities during 2013 primarily related to the purchase of long-term debt, the repurchase of our common stock, and payment of dividends.
We redeemed all $600.0 in aggregate principal amount of our 10.00% Notes.
In addition, we repurchased 31.8 shares of our common stock for an aggregate cost of $481.8, including fees, and made dividend payments of $126.0 on our common stock.
Net cash provided by financing activities during 2012 primarily reflected net proceeds from our debt transactions.
We issued $300.0 in aggregate principal amount of 2.25% Senior Notes due 2017 (the “2.25% Notes”), $500.0 in aggregate principal amount of 3.75% Senior Notes due 2023 (the “3.75% Notes”) and $250.0 in aggregate principal amount of 4.00% Senior Notes due 2022 (the “4.00% Notes”).
The proceeds from the issuance of the 4.00% Notes were applied towards the repurchase and redemption of $399.6 in aggregate principal amount of our 4.25% Notes.
Offsetting the net proceeds from our debt transactions was the repurchase of 32.7 shares of our common stock for an aggregate cost of $350.5, including fees, and dividend payments of $103.4 on our common stock.
Foreign Exchange Rate Changes The effect of foreign exchange rate changes on cash and cash equivalents included in the Consolidated Statements of Cash Flows resulted in a decrease of $94.1 in 2013.
The decrease was primarily a result of the U. S.  Dollar being stronger than several foreign currencies, including the Australian Dollar, Brazilian Real, Japanese Yen, Canadian Dollar and South African Rand as of December 31, 2013 compared to December 31, 2012.
The effect of foreign exchange rate changes on cash and cash equivalents included in the Consolidated Statements of Cash Flows resulted in a decrease of $6.2 in 2012.
The decrease was a result of the U. S.  Dollar being stronger than several foreign currencies, including the Brazilian Real and South African Rand, offset by the U. S.  Dollar being weaker than other foreign currencies, including the Australian Dollar, British Pound and the Euro, as of as of December 31, 2012 compared to December 31, 2011.
## Table 2 ##
LIQUIDITY OUTLOOK We expect our cash flow from operations, cash and cash equivalents to be sufficient to meet our anticipated operating requirements at a minimum for the next twelve months.
We also have a committed corporate credit facility as well as uncommitted facilities available to support our operating needs.
We continue to maintain a disciplined approach to managing liquidity, with flexibility over significant uses of cash, including our capital expenditures, cash used for new acquisitions, our common stock repurchase program and our common stock dividends.
Management’s Discussion and Analysis of Financial Condition and Results of Operations – (continued) (Amounts in Millions, Except Per Share Amounts) factors will likely differ from the estimates used in our valuation, and it is possible that differences and changes could be material.
A deterioration in profitability, adverse market conditions, significant client losses, changes in spending levels of our existing clients or a different economic outlook than currently estimated by management could have a significant impact on the estimated fair value of our reporting units and could result in an impairment charge in the future.
We also perform a sensitivity analysis to detail the impact that changes in assumptions may have on the outcome of the first step of the impairment test.
Our sensitivity analysis provides a range of fair value for each reporting unit, where the low end of the range reduces growth rates by 0.25% and increases discount rates by 0.5%, and the high end of the range increases growth rates by 0.25% and decreases discount rates by 0.5%.
We use the average of our fair values for purposes of our comparison between carrying value and fair value for the first step of the quantitative impairment test.
The table below displays the goodwill midpoint of the range for each reporting unit tested in the 2013 and 2012 annual impairment tests.
Our results of the comparison between carrying value and fair value at the average fair value indicated that for the 2013 test there was one reporting unit and for the 2012 test there were no reporting units whose fair value exceeded its carrying value by less than 20%
## Table 3 ##
Additionally, we performed a sensitivity analysis and reviewed the carrying values compared to the high end and low end of the valuation range.
The table below displays the range of the sensitivity analysis for each reporting unit tested in the 2013 and 2012 annual impairment tests.
For the 2013 test, using the low of the valuation range, there were two reporting units whose fair value exceeded its carrying value by less than 20%, but not less that 0%.
For the 2012 test, using the low of the valuation range, there were no reporting units whose fair value exceeded its carrying value by less than 20%.
## Table 4 ##
Based on the analysis described above, for the reporting units for which we performed the first step of the quantitative impairment test, we concluded that our goodwill was not impaired as of October 1, 2013, because these reporting units passed the first step of the test as the fair values of each of the reporting units were substantially in excess of their respective net book values.
We review intangible assets with definite lives subject to amortization whenever events or circumstances indicate that a carrying amount of an asset may not be recoverable.
Recoverability of these assets is determined by comparing the carrying value of these assets to the estimated undiscounted future cash flows expected to be generated by these assets.
These assets
Item 7A.
Quantitative and Qualitative Disclosures About Market Risk (Amounts in millions) In the normal course of business, we are exposed to market risks related to interest rates, foreign currency rates and certain balance sheet items.
From time to time, we use derivative instruments, pursuant to established guidelines and policies, to manage some portion of these risks.
Derivative instruments utilized in our hedging activities are viewed as risk management tools and are not used for trading or speculative purposes.
Interest Rates Our exposure to market risk for changes in interest rates relates primarily to the fair market value and cash flows of our debt obligations.
The majority of our debt (approximately 89% and 93% as of December 31, 2013 and 2012, respectively) bears interest at fixed rates.
We do have debt with variable interest rates, but a 10% increase or decrease in interest rates would not be material to our interest expense or cash flows.
The fair market value of our debt is sensitive to changes in interest rates, and the impact of a 10% change in interest rates is summarized below.
## Table 5 ##
We have used interest rate swaps for risk management purposes to manage our exposure to changes in interest rates.
We do not have any interest rate swaps outstanding as of December 31, 2013.
We had $1,642.1 of cash, cash equivalents and marketable securities as of December 31, 2013 that we generally invest in conservative, short-term bank deposits or securities.
The interest income generated from these investments is subject to both domestic and foreign interest rate movements.
During 2013 and 2012, we had interest income of $24.7 and $29.5, respectively.
Based on our 2013 results, a 100-basis-point increase or decrease in interest rates would affect our interest income by approximately $16.4, assuming that all cash, cash equivalents and marketable securities are impacted in the same manner and balances remain constant from year-end 2013 levels.
Foreign Currency Rates We are subject to translation and transaction risks related to changes in foreign currency exchange rates.
Since we report revenues and expenses in U. S.  Dollars, changes in exchange rates may either positively or negatively affect our consolidated revenues and expenses (as expressed in U. S.  Dollars) from foreign operations.
The primary foreign currencies that impacted our results during 2013 were the Australian Dollar, Brazilian Real, Euro, Japanese Yen and the South African Rand.
Based on 2013 exchange rates and operating results, if the U. S.  Dollar were to strengthen or weaken by 10%, we currently estimate operating income would decrease or increase between 3% and 4%, assuming that all currencies are impacted in the same manner and our international revenue and expenses remain constant at 2013 levels.
The functional currency of our foreign operations is generally their respective local currency.
Assets and liabilities are translated at the exchange rates in effect at the balance sheet date, and revenues and expenses are translated at the average exchange rates during the period presented.
The resulting translation adjustments are recorded as a component of accumulated other comprehensive loss, net of tax, in the stockholders’ equity section of our Consolidated Balance Sheets.
Our foreign subsidiaries generally collect revenues and pay expenses in their functional currency, mitigating transaction risk.
However, certain subsidiaries may enter into transactions in currencies other than their functional currency.
Assets and liabilities denominated in currencies other than the functional currency are susceptible to movements in foreign currency until final settlement.
Currency transaction gains or losses primarily arising from transactions in currencies other than the functional currency are included in office and general expenses.
We have not entered into a material amount of foreign currency forward exchange contracts or other derivative financial instruments to hedge the effects of potential adverse fluctuations in foreign currency exchange rates.

<table><tr><td></td><td colspan="6">Consolidated Revenues for the Three Months Ended</td></tr><tr><td></td><td colspan="2">2013</td><td colspan="2">2012</td><td colspan="2">2011</td></tr><tr><td>(Amounts in Millions)</td><td></td><td>% of Total</td><td></td><td>% of Total</td><td></td><td>% of Total</td></tr><tr><td>March 31</td><td>$1,543.0</td><td>21.7%</td><td>$1,506.8</td><td>21.7%</td><td>$1,474.8</td><td>21.0%</td></tr><tr><td>June 30</td><td>1,756.2</td><td>24.7%</td><td>1,715.7</td><td>24.7%</td><td>1,740.7</td><td>24.8%</td></tr><tr><td>September 30</td><td>1,700.4</td><td>23.9%</td><td>1,670.4</td><td>24.0%</td><td>1,726.5</td><td>24.6%</td></tr><tr><td>December 31</td><td>2,122.7</td><td>29.7%</td><td>2,063.3</td><td>29.6%</td><td>2,072.6</td><td>29.6%</td></tr><tr><td></td><td>$7,122.3</td><td></td><td>$6,956.2</td><td></td><td>$7,014.6</td><td></td></tr></table>
<table><tr><td></td><td>Years ended December 31,</td></tr><tr><td>Cash Flow Data</td><td>2013</td><td>2012</td><td>2011</td></tr><tr><td>Net income, adjusted to reconcile net income to net cashprovided by operating activities<sup>1</sup></td><td>$598.4</td><td>$697.2</td><td>$735.7</td></tr><tr><td>Net cash used in working capital ²</td><td>-9.6</td><td>-293.2</td><td>-359.4</td></tr><tr><td>Changes in other non-current assets and liabilities using cash</td><td>4.1</td><td>-46.8</td><td>-102.8</td></tr><tr><td>Net cash provided by operating activities</td><td>$592.9</td><td>$357.2</td><td>$273.5</td></tr><tr><td>Net cash used in investing activities</td><td>-224.5</td><td>-210.2</td><td>-58.8</td></tr><tr><td>Net cash (used in) provided by financing activities</td><td>-1,212.3</td><td>131.3</td><td>-541.0</td></tr></table>
<table><tr><td></td><td>December 31,</td></tr><tr><td>Balance Sheet Data</td><td>2013</td><td>2012</td></tr><tr><td>Cash, cash equivalents and marketable securities</td><td>$1,642.1</td><td>$2,590.8</td></tr><tr><td>Short-term borrowings</td><td>$179.1</td><td>$172.1</td></tr><tr><td>Current portion of long-term debt</td><td>353.6</td><td>216.6</td></tr><tr><td>Long-term debt</td><td>1,129.8</td><td>2,060.8</td></tr><tr><td>Total debt</td><td>$1,662.5</td><td>$2,449.5</td></tr></table>
<table><tr><td></td><td colspan="2">2013 Impairment Test</td><td></td><td colspan="2">2012 Impairment Test</td></tr><tr><td>Reporting Unit</td><td>Goodwill</td><td>Fair value exceeds carrying value by:</td><td>Reporting Unit</td><td>Goodwill</td><td>Fair value exceeds carrying value by:</td></tr><tr><td>A</td><td>$583.4</td><td>> 25%</td><td>A</td><td>$450.2</td><td>> 60%</td></tr><tr><td>B</td><td>$496.1</td><td>> 660%</td><td>B</td><td>$1,090.3</td><td>> 45%</td></tr><tr><td>C</td><td>$209.1</td><td>> 35%</td><td></td><td></td><td></td></tr><tr><td>D</td><td>$25.8</td><td>> 255%</td><td></td><td></td><td></td></tr><tr><td>E</td><td>$197.3</td><td>> 30%</td><td></td><td></td><td></td></tr><tr><td>F</td><td>$182.1</td><td>> 50%</td><td></td><td></td><td></td></tr><tr><td>G</td><td>$66.8</td><td>> 10%</td><td></td><td></td><td></td></tr></table>
<table><tr><td></td><td colspan="3">2013 Impairment Test</td><td></td><td colspan="3">2012 Impairment Test</td></tr><tr><td>Reporting Unit</td><td>Goodwill</td><td colspan="2">Fair value exceeds carrying value by:</td><td>Reporting Unit</td><td>Goodwill</td><td colspan="2">Fair value exceeds carrying value by:</td></tr><tr><td></td><td></td><td>Low</td><td>High</td><td></td><td></td><td>Low</td><td>High</td></tr><tr><td>A</td><td>$583.4</td><td>> 15%</td><td>> 30%</td><td>A</td><td>$450.2</td><td>> 25%</td><td>> 95%</td></tr><tr><td>B</td><td>$496.1</td><td>> 600%</td><td>> 700%</td><td>B</td><td>$1,090.3</td><td>> 35%</td><td>> 55%</td></tr><tr><td>C</td><td>$209.1</td><td>> 30%</td><td>> 40%</td><td></td><td></td><td></td><td></td></tr><tr><td>D</td><td>$25.8</td><td>> 240%</td><td>> 275%</td><td></td><td></td><td></td><td></td></tr><tr><td>E</td><td>$197.3</td><td>> 20%</td><td>> 35%</td><td></td><td></td><td></td><td></td></tr><tr><td>F</td><td>$182.1</td><td>> 40%</td><td>> 60%</td><td></td><td></td><td></td><td></td></tr><tr><td>G</td><td>$66.8</td><td>> 2%</td><td>> 20%</td><td></td><td></td><td></td><td></td></tr></table>
<table><tr><td></td><td>Increase/(Decrease)in Fair Market Value</td></tr><tr><td>As of December 31,</td><td>10% Increasein Interest Rates</td><td>10% Decreasein Interest Rates</td></tr><tr><td>2013</td><td>$-26.9</td><td>$27.9</td></tr><tr><td>2012</td><td>-27.5</td><td>28.4</td></tr></table>

Question: what is the statistical interval that interest income can be affected during the next year based on the data from 2013?