AMERICAN TOWER CORPORATION AND SUBSIDIARIES NOTES TO CONSOLIDATED FINANCIAL STATEMENTS F-9 business combinations and acquisitions of assets.
The Company considers events or transactions that occur after the balance sheet date but before the financial statements are issued as additional evidence for certain estimates or to identify matters that require additional disclosure.
Accounts Receivable and Deferred Rent Asset—The Company derives the largest portion of its revenues, corresponding accounts receivable and the related deferred rent asset from a relatively small number of tenants in the telecommunications industry, and 56% of its current year revenues are derived from four tenants.
The Company’s deferred rent asset is associated with non-cancellable tenant leases that contain fixed escalation clauses over the terms of the applicable lease in which revenue is recognized on a straight-line basis over the lease term.
The Company mitigates its concentrations of credit risk with respect to notes and trade receivables and the related deferred rent assets by actively monitoring the creditworthiness of its borrowers and tenants.
In recognizing tenant revenue, the Company assesses the collectibility of both the amounts billed and the portion recognized in advance of billing on a straight-line basis.
This assessment takes tenant credit risk and business and industry conditions into consideration to ultimately determine the collectibility of the amounts billed.
To the extent the amounts, based on management’s estimates, may not be collectible, recognition is deferred until such point as collectibility is determined to be reasonably assured.
Any amounts that were previously recognized as revenue and subsequently determined to be uncollectible are charged to bad debt expense included in Selling, general, administrative and development expense in the accompanying consolidated statements of operations.
Accounts receivable is reported net of allowances for doubtful accounts related to estimated losses resulting from a tenant’s inability to make required payments and allowances for amounts invoiced whose collectibility is not reasonably assured.
These allowances are generally estimated based on payment patterns, days past due and collection history, and incorporate changes in economic conditions that may not be reflected in historical trends, such as tenants in bankruptcy, liquidation or reorganization.
Receivables are written-off against the allowances when they are determined to be uncollectible.
Such determination includes analysis and consideration of the particular conditions of the account.
Changes in the allowances were as follows (in thousands):
## Table 0 ##
(1) Recoveries includes recognition of revenue resulting from collections of previously reserved amounts.
Functional Currency—The functional currency of each of the Company’s foreign operating subsidiaries is the respective local currency, except for Costa Rica, where the functional currency is the U. S.  Dollar.
All foreign currency assets and liabilities held by the subsidiaries are translated into U. S.  Dollars at the exchange rate in effect at the end of the applicable fiscal reporting period and all foreign currency revenues and expenses are translated at the average monthly exchange rates.
Translation adjustments are reflected in equity as a component of AOCI in the consolidated balance sheets and included as a component of Comprehensive income (loss) in the consolidated statements of comprehensive income (loss).
Transactional gains and losses on foreign currency transactions are reflected in Other expense in the consolidated statements of operations.
However, the effect from fluctuations in foreign currency exchange rates on intercompany debt that is considered to be permanently reinvested is reflected in AOCI in the consolidated balance sheets and included as a component of comprehensive income (loss).
During the year ended December 31, 2016, the Company recorded net foreign currency losses of $153.9 million, of which $105.0 million was recorded in AOCI and $48.9 million was recorded in Other expense.
Cash and Cash Equivalents—Cash and cash equivalents include cash on hand, demand deposits and short-term investments with original maturities of three months or less.
The Company maintains its deposits at high quality financial institutions and monitors the credit ratings of those institutions.
Restricted Cash—Restricted cash includes cash pledged as collateral to secure obligations and all cash whose use is otherwise limited by contractual provisions.
Steam Sales and Deliveries CECONY’s steam sales and deliveries for the last five years were:
## Table 1 ##
For further discussion of the company’s steam operating revenues and its steam results, see “Results of Operations” in Item 7.
For additional segment information, see Note N to the financial statements in Item 8.
Steam Peak Demand and Capacity Demand for steam in CECONY’s service area peaks during the winter heating season.
The one-hour peak demand during the winter of 2018/2019 (through January 31, 2019) occurred on January 31, 2019 when the demand reached approximately 8.4 MMlb per hour.
“Design weather conditions” for the steam system is a standard to which the actual peak demand is adjusted for evaluation and planning purposes.
The company’s estimate for the winter of 2019/2020 peak demand of its steam customers is about 8.9 MMlb per hour under design weather conditions.
As of January 2019, the company forecasts an average annual decrease in steam peak demand in its service area at design weather conditions over the next five years to be approximately 0.5 percent.
On December 31, 2018, the steam system was capable of delivering approximately 11.4 MMlb of steam per hour, and CECONY estimates that the system will have the same capability in the 2019/2020 winter.
Steam Supply 40 percent of the steam produced by CECONY in 2018 was supplied by the company’s steam-only generating assets; 42 percent was produced by the company’s steam-electric generating assets, where steam and electricity are primarily cogenerated; and 18 percent was purchased under an agreement with Brooklyn Navy Yard Cogeneration Partners L. P.  O&R Electric Operations Electric Facilities O&R’s capitalized costs for utility plant, net of accumulated depreciation, for distribution facilities were $1,034 million and $963 million at December 31, 2018 and 2017, respectively.
For its transmission facilities, the costs for utility plant, net of accumulated depreciation, were $227 million and $220 million at December 31, 2018 and 2017, respectively.
O&R and RECO own, in whole or in part, transmission and distribution facilities which include 549 circuit miles of transmission lines, 15 transmission substations, 63 distribution substations, 88,545 in-service line transformers, 3,748 pole miles of overhead distribution lines and 2,181 miles of underground distribution lines.
O&R’s transmission system is part of the NYISO system except that portions of RECO’s system are located within the transmission area controlled by PJM.
Electric Sales and Deliveries O&R delivers electricity to its full-service customers who purchase electricity from the company.
The company also delivers electricity to its customers who purchase electricity from other suppliers through the company’s retail choice program
South America.
Approximately 26% of 2017 net sales were to international markets.
This segment sells directly through its own sales force and indirectly through independent manufacturers’ representatives, primarily to wholesalers, home centers, mass merchandisers and industrial distributors.
In aggregate, sales to The Home Depot and Lowe’s comprised approximately 23% of net sales of the Plumbing segment in 2017.
This segment’s chief competitors include Delta (owned by Masco), Kohler, Pfister (owned by Spectrum Brands), American Standard (owned by LIXIL Group), InSinkErator (owned by Emerson Electronic Company) and imported private-label brands.
Doors.
Our Doors segment manufactures and sells fiberglass and steel entry door systems under the Therma-Tru brand and urethane millwork product lines under the Fypon brand.
This segment benefits from the long-term trend away from traditional materials, such as wood, steel and aluminum, toward more energy-efficient and durable synthetic materials.
Therma-Tru products include fiberglass and steel residential entry door and patio door systems, primarily for sale in the U. S.  and Canada.
This segment’s principal customers are home centers, millwork building products and wholesale distributors, and specialty dealers that provide products to the residential new construction market, as well as to the remodeling and renovation markets.
In aggregate, sales to The Home Depot and Lowe’s comprised approximately 14% of net sales of the Doors segment in 2017.
This segment’s competitors include Masonite, JELD-WEN, Plastpro and Pella.
Security.
Our Security segment’s products consist of locks, safety and security devices, and electronic security products manufactured, sourced and distributed primarily under the Master Lock brand and fire resistant safes, security containers and commercial cabinets manufactured, sourced and distributed under the SentrySafe brand.
This segment sells products principally in the U. S. , Canada, Europe, Central America, Japan and Australia.
Approximately 25% of 2017 net sales were to international markets.
This segment manufactures and sells key-controlled and combination padlocks, bicycle and cable locks, built-in locker locks, door hardware, automotive, trailer and towing locks, electronic access control solutions, and other specialty safety and security devices for consumer use to hardware, home center and other retail outlets.
In addition, the segment sells lock systems and fire resistant safes to locksmiths, industrial and institutional users, and original equipment manufacturers.
In aggregate, sales to The Home Depot and Lowe’s comprised approximately 18% of the net sales of the Security segment in 2017.
Master Lock competes with Abus, W. H.  Brady, Hampton, Kwikset (owned by Spectrum Brands), Schlage (owned by Allegion), Assa Abloy and various imports, and SentrySafe competes with First Alert, Magnum, Fortress, Stack-On and Fire King.
Annual net sales for each of the last three fiscal years for each of our business segments were as follows:
## Table 2 ##
For additional financial information for each of our business segments, refer to Note 18, “Information on Business Segments,” to the Consolidated Financial Statements in Item 8 of this Annual Report on Form 10-K.  Other Information Raw materials.
The table below indicates the principal raw materials used by each of our segments.
These materials are available from a number of sources.
Volatility in the prices of commodities and energy used in making and distributing our products impacts the cost of manufacturing our products.
News UK Revenues at the U. K.  newspapers for the fiscal year ended June 30, 2016 decreased 10% as compared to fiscal 2015.
Advertising revenues decreased $63 million, primarily due to print market declines and the negative impact of foreign currency fluctuations.
Circulation and subscription revenues decreased $41 million due to the negative impact of foreign currency fluctuations.
Lower revenues resulting from single-copy volume declines, primarily at The Sun, and changes in the digital strategy at The Sun, were offset by cover price increases, higher subscriptions at The Times and The Sunday Times and the positive impact of the 53rd week.
Other revenues decreased $38 million due to a reduction in newsprint sales to third parties.
The impact of this revenue decrease was offset in large part by lower operating expenses.
The impact of foreign currency fluctuations of the U. S.  dollar against the British pound resulted in a revenue decrease of $80 million, or 6%, for the fiscal year ended June 30, 2016 as compared to fiscal 2015.
Dow Jones Revenues for the fiscal year ended June 30, 2016 were relatively flat as compared to fiscal 2015.
Circulation and subscription revenues increased by $33 million, primarily due to price increases and digital volume growth at The Wall Street Journal, modest growth in subscription revenues in the professional information business and the positive impact of the 53rd week, partially offset by the negative impact of foreign currency fluctuations.
This increase was partially offset by lower advertising revenues of $27 million as a result of lower print advertising, partially offset by higher digital advertising revenues and the positive impact of the 53rd week.
The impact of foreign currency fluctuations of the U. S.  dollar against local currencies resulted in a revenue decrease of $10 million, or 1%, for the fiscal year ended June 30, 2016 as compared to fiscal 2015.
News America Marketing Revenues at News America Marketing decreased 6% for the fiscal year ended June 30, 2016 as compared to fiscal 2015, primarily due to decreased revenues for free-standing insert products of $98 million, partially offset by increased in-store product revenues of $18 million.
Book Publishing (20% of the Company’s consolidated revenues in fiscal 2016 and 2015)
## Table 3 ##
For the fiscal year ended June 30, 2016, revenues at the Book Publishing segment decreased $21 million, or 1%, as compared to fiscal 2015.
The decrease was primarily the result of $69 million in higher sales of the Divergent series by Veronica Roth and American Sniper by Chris Kyle in the prior year, an industry-wide decline in e-book sales and the negative impact of foreign currency fluctuations.
These decreases were partially offset by higher print book sales across all genres, including sales of Go Set a Watchman by Harper Lee in fiscal 2016 of $42 million, and $23 million related to the acquisition of Harlequin in August 2014.
The Company sold 2.0 million net units of the Divergent series in the fiscal year ended June 30, 2016 as compared to 8.3 million net units in fiscal 2015.
The impact of foreign currency fluctuations of the U. S.  dollar against local currencies resulted in a revenue decrease of $39 million, or 2%, for the fiscal year ended June 30, 2016 as compared to

<table><tr><td></td><td colspan="3">Year Ended December 31,</td></tr><tr><td></td><td>2016</td><td>2015</td><td>2014</td></tr><tr><td>Balance as of January 1</td><td>$23,096</td><td>$17,306</td><td>$19,895</td></tr><tr><td>Current year increases</td><td>49,966</td><td>19,878</td><td>8,243</td></tr><tr><td>Write-offs, recoveries and other -1</td><td>-27,174</td><td>-14,088</td><td>-10,832</td></tr><tr><td>Balance as of December 31,</td><td>$45,888</td><td>$23,096</td><td>$17,306</td></tr></table>
<table><tr><td></td><td colspan="5">Year Ended December 31,</td></tr><tr><td></td><td>2014</td><td>2015</td><td>2016</td><td>2017</td><td>2018</td></tr><tr><td>Steam Sold(MMlb)</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>General</td><td>594</td><td>538</td><td>465</td><td>490</td><td>593</td></tr><tr><td>Apartment house</td><td>6,574</td><td>6,272</td><td>5,792</td><td>5,754</td><td>6,358</td></tr><tr><td>Annual power</td><td>15,848</td><td>15,109</td><td>13,722</td><td>13,166</td><td>14,811</td></tr><tr><td>Total Steam Delivered to CECONY Customers</td><td>23,016</td><td>21,919</td><td>19,979</td><td>19,410</td><td>21,762</td></tr><tr><td>Steam Sold($ in millions)</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>General</td><td>$30</td><td>$29</td><td>$23</td><td>$26</td><td>$30</td></tr><tr><td>Apartment house</td><td>180</td><td>176</td><td>148</td><td>158</td><td>174</td></tr><tr><td>Annual power</td><td>469</td><td>453</td><td>378</td><td>392</td><td>441</td></tr><tr><td>Other operating revenues</td><td>-51</td><td>-29</td><td>2</td><td>19</td><td>-14</td></tr><tr><td>Total Steam Delivered to CECONY Customers</td><td>$628</td><td>$629</td><td>$551</td><td>$595</td><td>$631</td></tr><tr><td>Average Revenue per Mlb Sold</td><td>$29.50</td><td>$30.02</td><td>$27.48</td><td>$29.68</td><td>$29.64</td></tr></table>
<table><tr><td><i>(In millions)</i></td><td><i>2017</i></td><td><i>2016</i></td><td>2015</td></tr><tr><td>Cabinets</td><td>$2,467.1</td><td>$2,397.8</td><td>$2,173.4</td></tr><tr><td>Plumbing</td><td>1,720.8</td><td>1,534.4</td><td>1,414.5</td></tr><tr><td>Doors</td><td>502.9</td><td>473.0</td><td>439.1</td></tr><tr><td>Security</td><td>592.5</td><td>579.7</td><td>552.4</td></tr><tr><td>Total</td><td>$5,283.3</td><td>$4,984.9</td><td>$4,579.4</td></tr></table>
<table><tr><td></td><td colspan="4">For the fiscal years ended June 30,</td></tr><tr><td></td><td>2016</td><td>2015</td><td>Change</td><td> % Change</td></tr><tr><td> (in millions, except %)</td><td></td><td></td><td colspan="2">Better/(Worse)</td></tr><tr><td>Revenues:</td><td></td><td></td><td></td><td></td></tr><tr><td>Consumer</td><td>$1,578</td><td>$1,594</td><td>$-16</td><td>-1%</td></tr><tr><td>Other</td><td>68</td><td>73</td><td>-5</td><td>-7%</td></tr><tr><td> Total Revenues</td><td>1,646</td><td>1,667</td><td>-21</td><td>-1%</td></tr><tr><td>Operating expenses</td><td>-1,145</td><td>-1,106</td><td>-39</td><td>-4%</td></tr><tr><td>Selling, general and administrative</td><td>-316</td><td>-340</td><td>24</td><td>7%</td></tr><tr><td> Segment EBITDA</td><td>$185</td><td>$221</td><td>$-36</td><td>-16%</td></tr></table>

Question: Which year is Total Steam Delivered to CECONY Customers the most?
Answer: 2014