Taxing authorities could challenge our historical and future tax positions.
Our future effective tax rates could be affected by changes in the mix of earnings in countries with differing statutory rates and changes in tax laws or their interpretation including changes related to tax holidays or tax incentives.
Our taxes could increase if certain tax holidays or incentives are not renewed upon expiration, or if tax rates or regimes applicable to us in such jurisdictions are otherwise increased.
The amount of tax we pay is subject to our interpretation of applicable tax laws in the jurisdictions in which we file.
We have taken and will continue to take tax positions based on our interpretation of such tax laws.
In particular, we will seek to organize and operate ourselves in such a way that we are and remain tax resident in the United Kingdom.
Additionally, in determining the adequacy of our provision for income taxes, we regularly assess the likelihood of adverse outcomes resulting from tax examinations.
While it is often difficult to predict the final outcome or the timing of the resolution of a tax examination, our reserves for uncertain tax benefits reflect the outcome of tax positions that are more likely than not to occur.
While we believe that we have complied with all applicable tax laws, there can be no assurance that a taxing authority will not have a different interpretation of the law and assess us with additional taxes.
Should additional taxes be assessed, this may result in a material adverse effect on our results of operations and financial condition.
ITEM 1B.
UNRESOLVED STAFF COMMENTS We have no unresolved SEC staff comments to report.
ITEM 2.
PROPERTIES As of December 31, 2016, we owned or leased 126 major manufacturing sites and 15 major technical centers.
A manufacturing site may include multiple plants and may be wholly or partially owned or leased.
We also have many smaller manufacturing sites, sales offices, warehouses, engineering centers, joint ventures and other investments strategically located throughout the world.
We have a presence in 46 countries.
The following table shows the regional distribution of our major manufacturing sites by the operating segment that uses such facilities:
## Table 0 ##
In addition to these manufacturing sites, we had 15 major technical centers: five in North America; five in Europe, Middle East and Africa; four in Asia Pacific; and one in South America.
Of our 126 major manufacturing sites and 15 major technical centers, which include facilities owned or leased by our consolidated subsidiaries, 75 are primarily owned and 66 are primarily leased.
We frequently review our real estate portfolio and develop footprint strategies to support our customers’ global plans, while at the same time supporting our technical needs and controlling operating expenses.
We believe our evolving portfolio will meet current and anticipated future needs.
ITEM 3.
LEGAL PROCEEDINGS We are from time to time subject to various actions, claims, suits, government investigations, and other proceedings incidental to our business, including those arising out of alleged defects, breach of contracts, competition and antitrust matters, product warranties, intellectual property matters, personal injury claims and employment-related matters.
It is our opinion that the outcome of such matters will not have a material adverse impact on our consolidated financial position, results of operations, or cash flows.
With respect to warranty matters, although we cannot ensure that the future costs of warranty claims by customers will not be material, we believe our established reserves are adequate to cover potential warranty settlements.
However, the final amounts required to resolve these matters could differ materially from our recorded estimates.
WASTE MANAGEMENT, INC.  NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued) Dividends Our quarterly dividends have been declared by our Board of Directors and paid in accordance with the capital allocation programs discussed above.
The following is a summary of dividends declared and paid each year:
## Table 1 ##
(a) In 2006, the cash dividend declared amounts excluded the first quarterly dividend for 2006 of $0.22 per share, which was declared by the Board of Directors in 2005.
In December 2008, we announced that our Board of Directors expects to increase the per share quarterly dividend from $0.27 to $0.29 for dividends declared in 2009.
However, all future dividend declarations are at the discretion of the Board of Directors, and depend on various factors, including our net earnings, financial condition, cash required for future business plans and other factors the Board may deem relevant.15.
Stock-Based Compensation Employee Stock Purchase Plan We have an Employee Stock Purchase Plan under which employees that have been employed for at least 30 days may purchase shares of our common stock at a discount.
The plan provides for two offering periods for purchases: January through June and July through December.
At the end of each offering period, employees are able to purchase shares of common stock at a price equal to 85% of the lesser of the market value of the stock on the first and last day of such offering period.
The purchases are made through payroll deductions, and the number of shares that may be purchased is limited by IRS regulations.
The total number of shares issued under the plan for the offering periods in each of 2008, 2007 and 2006 was approximately 839,000, 713,000, and 644,000, respectively.
Including the impact of the January 2009 issuance of shares associated with the July to December 2008 offering period, approximately 470,000 shares remain available for issuance under the plan.
Our Employee Stock Purchase Plan is “compensatory” under the provisions of SFAS No.123 (revised 2004), Share-Based Payment.
Accordingly, beginning with our adoption of SFAS No.123(R) on January 1, 2006 we recognize compensation expense associated with our employees’ participation in the Stock Purchase Plan.
Our Employee Stock Purchase Plan increased annual compensation expense by approximately $6 million, or $4 million net of tax, for 2008 and approximately $5 million, or $3 million net of tax, for both 2007 and 2006.
Employee Stock Incentive Plans Pursuant to our stock incentive plan, we have the ability to issue stock options, stock awards and stock appreciation rights, all on terms and conditions determined by the Management Development and Compensation Committee of our Board of Directors.
Since May 2004, all stock-based compensation awards described herein have been made under the Company’s 2004 Stock Incentive Plan, which authorizes the issuance of a maximum of 34 million shares of our common stock.
We currently utilize treasury shares to meet the needs of our equity-based compensation programs under the 2004 Stock Incentive Plan and to settle outstanding awards granted pursuant to previous incentive plans.
Our operating revenues generally come from fees charged for our collection, disposal, transfer, Wheelabrator and recycling services.
Revenues from our collection operations are influenced by factors such as collection frequency, type of collection equipment furnished, type and volume or weight of the waste collected, distance to the disposal facility and our disposal costs.
Revenues from our landfill operations consist of tipping fees, which are generally based on the weight, volume and type of waste being disposed of at our disposal facilities.
Fees charged at transfer stations are generally based on the volume of waste deposited, taking into account our cost of loading, transporting and disposing of the solid waste at a disposal site.
Our Wheelabrator revenues are based on the type and volume of waste received at our waste-to-energy facilities and IPPs and fees charged for the sale of energy and steam.
Recycling revenue, which is generated by our WMRA Group as well as recycling operations embedded in the operations of our four geographic operating Groups, generally consists of tipping fees and the sale of recyclable commodities to third parties.
The fees we charge for our collection, disposal, transfer and recycling services generally include fuel surcharges, which are indexed to current market costs for fuel.
Our “other” revenues include our in-plant services, methane gas recovery, Port-O-Let?
services, street and parking lot sweeping services, portable self-storage, fluorescent lamp recycling and healthcare solutions services.
Intercompany revenues between our operations have been eliminated in the consolidated financial statements.
The mix of operating revenues from our different services is reflected in the table below (in millions):
## Table 2 ##
The following table provides details associated with the period-to-period change in revenues (dollars in millions) and includes internal revenue growth calculated as a percentage of revenues from related business and as a percentage of total Company revenues:
## Table 3 ##
The expense declines noted above were largely offset by the impacts of the following: ?
a $32 million charge to landfill operating costs for the closed landfills that are managed by our closed sites management group through our Corporate organization, due to a sharp decline in United States Treasury rates in late 2008, which caused an increase in the present value of our environmental remediation obligations; and ?
costs incurred for the potential acquisition of Republic during the third quarter of 2008.
The decline in expenses when comparing 2007 with 2006 was primarily due to: ?
significantly lower risk management costs largely due to our focus on safety and controlling costs; ?
a reduction in expenses from the discontinuation of depreciation for certain enterprise-wide software; and ?
a $20 million charge recorded in 2006 to recognize unrecorded obligations associated with unclaimed property.
The expense declines noted above were offset, in part, by the impacts of the following: ?
increased spending on the support and development of our information technology, people and pricing strategic initiatives; ?
increased labor and related benefits costs; and ?
restructuring charges recognized during the first quarter of 2007.
Other Components of Net Income The following table summarizes the other major components of our income for the year ended December 31 for each respective period (dollars in millions):
## Table 4 ##
* Percentage change does not provide a meaningful comparison.
Refer to the explanations of these items below for a discussion of the relationship between current year and prior year activity.
Interest Expense Although our outstanding debt balances are relatively consistent year-over-year, the decline in interest costs when comparing 2008 with 2007 is generally related to (i) the maturity of higher rate debt that we have refinanced at lower interest rates; (ii) significant declines in market interest rates, which impact the interest expense associated with our interest rate swaps and our variable rate debt; and (iii) the early redemption of $244 million of 8.75% senior notes during the second quarter of 2008, which resulted in the recognition of a reduction in interest expense of approximately $10 million for the immediate recognition of fair value adjustments associated with terminated interest rate swaps that had been deferred and were being amortized over the life of the debt.
The decrease in interest expense when comparing 2007 with 2006 is largely related to a decrease in our average debt balances.
We use interest rate derivative contracts to manage our exposure to changes in market interest rates.
The combined impact of active and terminated interest rate swap agreements resulted in a net interest expense decrease of $50 million for 2008 and net interest expense increases of $11 million for 2007 and $4 million for 2006.
Our active interest rate swaps decreased our interest expense in 2008 by $8 million compared with an increase in interest expense in 2007 from active hedges of $48 million.
The significant change in the impact of our active interest rate swaps when comparing 2008 with 2007 has been driven by the decrease in short-term market interest rates, which
December 31, 2007 (representing a 2.3 percentage point reduction in our effective tax rate) and $149 million for the year ended December 31, 2006 (representing a 10.1 percentage point reduction in our effective tax rate).  ?
Non-conventional fuel tax credits — Through December 31, 2007, non-conventional fuel tax credits were derived from our landfills and our investments in the two coal-based, synthetic fuel production facilities discussed in the Equity in net losses of unconsolidated entities section above.
Pursuant to Section 45K of the Internal Revenue Code, these tax credits were phased-out if the price of oil exceeded an annual average as determined by the IRS.
Based on an estimated phase-out of 69% of Section 45K tax credits generated during 2007, our income taxes for the year ended December 31, 2007 included $50 million of non-conventional fuel tax credits.
These tax credits resulted in a 2.9 percentage point reduction in our effective tax rate for the year ended December 31, 2007.
In April 2008, the IRS published the phase-out percentage that must be applied to Section 45K tax credits generated in 2007, which was 67.2%.
Our provision for income taxes for the first quarter of 2008 included an adjustment of our 2007 year-end estimate to the final 2007 phase-out, which resulted in the recognition of a $3 million benefit.
Our income taxes for the year ended December 31, 2006 included $71 million of non-conventional fuel tax credits, resulting in a 4.8 percentage point reduction in our effective tax rate.
Non-conventional fuel tax credits expired at the end of 2007 pursuant to Section 45K of the Internal Revenue Code.
Other items that have affected our reported income taxes during the reported periods include the following: ?
Canadian tax rate changes and the related revaluation of deferred tax balances resulted in a $30 million tax benefit during 2007 compared with a $20 million tax benefit in 2006.
We did not have any comparable adjustments during the year ended December 31, 2008.  ?
We recorded reductions to income tax expense of $8 million in 2008, $9 million in 2007 and $20 million in 2006 due to state-related tax items.
These impacts were generally due to either (i) the revaluation of net accumulated deferred tax liabilities as a result of a decrease in our effective state tax rate or (ii) the expected utilization of state net operating loss and credit carryforwards.
Landfill and Environmental Remediation Discussion and Analysis We owned or operated 267 solid waste and six hazardous waste landfills at December 31, 2008 and we owned or operated 271 solid waste and six hazardous waste landfills at December 31, 2007.
At December 31, 2008 and 2007, the expected remaining capacity in cubic yards and tonnage of waste that can be accepted at our owned or operated landfills is shown below (in millions):

<table><tr><td></td><td>North America</td><td>Europe,Middle East& Africa</td><td>Asia Pacific</td><td>South America</td><td>Total</td></tr><tr><td>Electrical/Electronic Architecture</td><td>32</td><td>34</td><td>25</td><td>5</td><td>96</td></tr><tr><td>Powertrain Systems</td><td>4</td><td>8</td><td>5</td><td>1</td><td>18</td></tr><tr><td>Electronics and Safety</td><td>3</td><td>6</td><td>3</td><td>—</td><td>12</td></tr><tr><td>Total</td><td>39</td><td>48</td><td>33</td><td>6</td><td>126</td></tr></table>
<table><tr><td></td><td colspan="3"> Years Ended December 31,</td></tr><tr><td></td><td> 2008</td><td> 2007</td><td> 2006</td></tr><tr><td>Cash dividends per common share:</td><td></td><td></td><td></td></tr><tr><td>Declared(a)</td><td>$1.08</td><td>$0.96</td><td>$0.66</td></tr><tr><td>Paid</td><td>$1.08</td><td>$0.96</td><td>$0.88</td></tr><tr><td>Total cash dividends (in millions):</td><td></td><td></td><td></td></tr><tr><td>Declared(a)</td><td>$531</td><td>$495</td><td>$355</td></tr><tr><td>Paid</td><td>$531</td><td>$495</td><td>$476</td></tr></table>
<table><tr><td></td><td colspan="3">Years Ended December 31,</td></tr><tr><td></td><td>2008</td><td>2007</td><td>2006</td></tr><tr><td>Collection</td><td>$8,679</td><td>$8,714</td><td>$8,837</td></tr><tr><td>Landfill</td><td>2,955</td><td>3,047</td><td>3,197</td></tr><tr><td>Transfer</td><td>1,589</td><td>1,654</td><td>1,802</td></tr><tr><td>Wheelabrator</td><td>912</td><td>868</td><td>902</td></tr><tr><td>Recycling</td><td>1,180</td><td>1,135</td><td>905</td></tr><tr><td>Other</td><td>207</td><td>163</td><td>169</td></tr><tr><td>Intercompany</td><td>-2,134</td><td>-2,271</td><td>-2,449</td></tr><tr><td>Total</td><td>$13,388</td><td>$13,310</td><td>$13,363</td></tr></table>
<table><tr><td></td><td colspan="3">Period-to-Period Change 2008 vs. 2007</td><td colspan="3">Period-to-Period Change 2007 vs. 2006</td></tr><tr><td></td><td></td><td>As a% of</td><td>As a% of</td><td></td><td>As a% of</td><td>As a% of</td></tr><tr><td></td><td></td><td>Related</td><td>Total</td><td></td><td>Related</td><td>Total</td></tr><tr><td></td><td>Amount</td><td>Business(a)</td><td>Company(b)</td><td>Amount</td><td>Business(a)</td><td>Company(b)</td></tr><tr><td>Average yield:</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Solid waste</td><td>$347</td><td>3.2%</td><td>2.6%</td><td>$431</td><td>4.0%</td><td>3.3%</td></tr><tr><td>Waste-to-energy</td><td>19</td><td>2.7</td><td>0.2</td><td>1</td><td>0.1</td><td>—</td></tr><tr><td>Base business</td><td>366</td><td>3.2</td><td>2.8</td><td>432</td><td>3.7</td><td>3.3</td></tr><tr><td>Commodity</td><td>81</td><td>6.9</td><td>0.6</td><td>306</td><td>34.3</td><td>2.3</td></tr><tr><td>Electricity (IPPs)</td><td>8</td><td>10.8</td><td>0.1</td><td>2</td><td>2.7</td><td>—</td></tr><tr><td>Fuel surcharges and mandated fees</td><td>189</td><td>36.5</td><td>1.4</td><td>35</td><td>7.3</td><td>0.3</td></tr><tr><td>Total</td><td>644</td><td>4.9</td><td>4.9</td><td>775</td><td>5.9</td><td>5.9</td></tr><tr><td>Volume</td><td>-557</td><td></td><td>-4.2</td><td>-588</td><td></td><td>-4.5</td></tr><tr><td>Internal revenue growth</td><td>87</td><td></td><td>0.7</td><td>187</td><td></td><td>1.4</td></tr><tr><td>Acquisition</td><td>117</td><td></td><td>0.9</td><td>37</td><td></td><td>0.3</td></tr><tr><td>Divestitures</td><td>-130</td><td></td><td>-1.0</td><td>-320</td><td></td><td>-2.4</td></tr><tr><td>Foreign currency translation</td><td>4</td><td></td><td>—</td><td>43</td><td></td><td>0.3</td></tr><tr><td></td><td>$78</td><td></td><td>0.6%</td><td>$-53</td><td></td><td>-0.4%</td></tr></table>
<table><tr><td></td><td>2008</td><td colspan="2">Period-to- Period Change</td><td>2007</td><td colspan="2">Period-to- Period Change</td><td>2006</td></tr><tr><td>Interest expense</td><td>$-455</td><td>$66</td><td>-12.7%</td><td>$-521</td><td>$24</td><td>-4.4%</td><td>$-545</td></tr><tr><td>Interest income</td><td>19</td><td>-28</td><td>-59.6</td><td>47</td><td>-22</td><td>-31.9</td><td>69</td></tr><tr><td>Equity in net losses of unconsolidated entities</td><td>-4</td><td>31</td><td>*</td><td>-35</td><td>1</td><td>-2.8</td><td>-36</td></tr><tr><td>Minority interest</td><td>-41</td><td>5</td><td>-10.9</td><td>-46</td><td>-2</td><td>4.5</td><td>-44</td></tr><tr><td>Other, net</td><td>3</td><td>-1</td><td>-25.0</td><td>4</td><td>3</td><td>*</td><td>1</td></tr><tr><td>Provision for income taxes</td><td>669</td><td>129</td><td>*</td><td>540</td><td>215</td><td>*</td><td>325</td></tr></table>

Question: Which year is Fuel surcharges and mandated fees the highest?