DEVON ENERGY CORPORATION AND SUBSIDIARIES NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued) The following methods and assumptions were used to estimate the fair values in the tables above.
Fixed-income securities — Devon’s fixed-income securities consist of U. S.  Treasury obligations, bonds issued by investment-grade companies from diverse industries, and asset-backed securities.
These fixed-income securities are actively traded securities that can be redeemed upon demand.
The fair values of these Level 1 securities are based upon quoted market prices.
Devon’s fixed income securities also include commingled funds that primarily invest in long-term bonds and U. S.  Treasury securities.
These fixed income securities can be redeemed on demand but are not actively traded.
The fair values of these Level 2 securities are based upon the net asset values provided by the investment managers.
Equity securities — Devon’s equity securities include a commingled global equity fund that invests in large, mid and small capitalization stocks across the world’s developed and emerging markets.
These equity securities can be redeemed on demand but are not actively traded.
The fair values of these Level 2 securities are based upon the net asset values provided by the investment managers.
At December 31, 2010, Devon’s equity securities consisted of investments in U. S.  large and small capitalization companies and international large capitalization companies.
These equity securities were actively traded securities that could be redeemed upon demand.
The fair values of these Level 1 securities are based upon quoted market prices.
At December 31, 2010, Devon’s equity securities also included a commingled fund that invested in large capitalization companies.
These equity securities could be redeemed on demand but were not actively traded.
The fair values of these Level 2 securities are based upon the net asset values provided by the investment managers.
Other securities — Devon’s other securities include commingled, short-term investment funds.
These securities can be redeemed on demand but are not actively traded.
The fair values of these Level 2 securities are based upon the net asset values provided by investment managers.
Devon’s hedge fund and alternative investments include an investment in an actively traded global mutual fund that focuses on alternative investment strategies and a hedge fund of funds that invests both long and short using a variety of investment strategies.
Devon’s hedge fund of funds is not actively traded and Devon is subject to redemption restrictions with regards to this investment.
The fair value of this Level 3 investment represents the fair value as determined by the hedge fund manager.
Included below is a summary of the changes in Devon’s Level 3 plan assets (in millions).
## Table 0 ##
The Company routinely issues commercial paper as a source of short-term financing.
In April 2014, the Company entered into a $3.5 billion five-year revolving backup credit facility with various banks, which replaced a December 2010 $2.75 billion facility.
The credit facility is maintained to support general corporate purposes, including commercial paper borrowing.
The Company has not incurred any borrowings under this or previous facilities.
The credit facility contains no financial covenants and is not subject to termination based on a change of credit rating or material adverse changes.
The facility is unsecured and may be accessed under various interest rate and currency denomination alternatives at the Company’s option.
Fees to maintain the facility are immaterial.
(10) Long-Term Debt The details of long-term debt follow:
## Table 1 ##
Long-term debt maturing during each of the four years after 2018 is $683, $516, $299 and $500, respectively.
Total interest paid on all debt was approximately $192, $209 and $196 in 2017, 2016 and 2015, respectively.
During the year, the Company repaid $250 of 5.125% notes that matured in December 2016.
In 2016, the Company repaid $250 of 4.75% notes that matured in October 2015.
The Company maintains a universal shelf registration statement on file with the SEC under which it can issue debt securities, preferred stock, common stock, warrants, share purchase contracts or share purchase units without a predetermined limit.
Securities can be sold in one or more separate offerings with the size, price and terms to be determined at the time of sale.
(11) Retirement Plans Retirement plans expense includes the following components:
## Table 2 ##
The increase in net periodic pension expense in 2017 is attributable to higher amortization compared to the prior year.
Beginning in 2016, the Company refined the method used to determine the service and interest cost components of pension expense for its U. S.  retirement plans.
The specific spot rates along the yield curve, rather than the single weighted-average rate previously used, are applied to the projected cash flows to provide more precise measurement of these costs.
This is a change in estimate which has
Total cash paid for all businesses for the fiscal year ended 2018 was $2.2 billion, net of cash acquired.
The purchase price of the 2018 acquisitions was preliminarily allocated to assets and liabilities as follows.
Valuations of acquired assets and liabilities are in process and subject to refinement.
## Table 3 ##
Results of operations for the 2018 acquisitions included sales of $365 and a net loss of $3, including intangibles amortization of $40 and restructuring expense of $3.
These results also included first year pretax acquisition accounting charges related to inventory and deferred revenue of $39 and $11, respectively, which are reported in Corporate and other.
See Note 18.
On April 28, 2017, the Company completed the acquisition of Pentair’s valves & controls business for $2.96 billion, net of cash acquired of $207, subject to certain post-closing adjustments.
This business, with annualized sales of approximately $1.4 billion, is a manufacturer of control, isolation and pressure relief valves and actuators, and complements the Valves, Actuators & Regulators product offering within Automation Solutions.
The Company recognized goodwill of $1.5 billion (none of which is expected to be tax deductible), and other identifiable intangible assets of $1.1 billion, primarily customer relationships and intellectual property with a weighted-average life of approximately 14 years.
The Company also acquired two smaller businesses in the Automation Solutions segment.
Total cash paid for all businesses was $3.0 billion, net of cash acquired.
The purchase price of the valves & controls business was allocated to assets and liabilities as follows.

<table><tr><td>December 31, 2009</td><td>$51</td></tr><tr><td>Purchases</td><td>3</td></tr><tr><td>Investment returns</td><td>4</td></tr><tr><td>December 31, 2010</td><td>58</td></tr><tr><td>Purchases</td><td>33</td></tr><tr><td>Investment returns</td><td>-1</td></tr><tr><td>December 31, 2011</td><td>$90</td></tr></table>
<table><tr><td></td><td>2016</td><td>2017</td></tr><tr><td>5.125% notes due December 2016</td><td>$250</td><td>—</td></tr><tr><td>5.375% notes due October 2017</td><td>250</td><td>250</td></tr><tr><td>5.25% notes due October 2018</td><td>400</td><td>400</td></tr><tr><td>5.0% notes due April 2019</td><td>250</td><td>250</td></tr><tr><td>4.875% notes due October 2019</td><td>500</td><td>500</td></tr><tr><td>4.25% notes due November 2020</td><td>300</td><td>300</td></tr><tr><td>2.625% notes due December 2021</td><td>500</td><td>500</td></tr><tr><td>2.625% notes due February 2023</td><td>500</td><td>500</td></tr><tr><td>3.15% notes due June 2025</td><td>500</td><td>500</td></tr><tr><td>6.0% notes due August 2032</td><td>250</td><td>250</td></tr><tr><td>6.125% notes due April 2039</td><td>250</td><td>250</td></tr><tr><td>5.25% notes due November 2039</td><td>300</td><td>300</td></tr><tr><td>Other</td><td>68</td><td>64</td></tr><tr><td>Long-term debt</td><td>4,318</td><td>4,064</td></tr><tr><td>Less: Current maturities</td><td>267</td><td>270</td></tr><tr><td>Total, net</td><td>$4,051</td><td>3,794</td></tr></table>
<table><tr><td></td><td colspan="3">U.S. Plans</td><td colspan="3">Non-U.S. Plans</td></tr><tr><td></td><td>2015</td><td>2016</td><td>2017</td><td>2015</td><td>2016</td><td>2017</td></tr><tr><td>Defined benefit plans:</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Service cost (benefits earned during the period)</td><td>$69</td><td>59</td><td>60</td><td>37</td><td>26</td><td>19</td></tr><tr><td>Interest cost</td><td>182</td><td>148</td><td>134</td><td>46</td><td>39</td><td>30</td></tr><tr><td>Expected return on plan assets</td><td>-303</td><td>-296</td><td>-290</td><td>-58</td><td>-52</td><td>-56</td></tr><tr><td>Net amortization and other</td><td>174</td><td>166</td><td>211</td><td>20</td><td>17</td><td>22</td></tr><tr><td>Net periodic pension expense</td><td>122</td><td>77</td><td>115</td><td>45</td><td>30</td><td>15</td></tr><tr><td>Defined contribution plans</td><td>111</td><td>104</td><td>96</td><td>61</td><td>56</td><td>47</td></tr><tr><td>Total retirement plans expense</td><td>$233</td><td>181</td><td>211</td><td>106</td><td>86</td><td>62</td></tr></table>
<table><tr><td>Accounts receivable</td><td>$154</td></tr><tr><td>Inventory</td><td>196</td></tr><tr><td>Property, plant and equipment</td><td>129</td></tr><tr><td>Goodwill</td><td>1,188</td></tr><tr><td>Intangibles</td><td>1,012</td></tr><tr><td>Other assets</td><td>45</td></tr><tr><td>Total assets</td><td>2,724</td></tr><tr><td>Accounts payable</td><td>73</td></tr><tr><td>Other current liabilities</td><td>112</td></tr><tr><td>Deferred taxes and other liabilities</td><td>320</td></tr><tr><td>Cash paid, net of cash acquired</td><td>$2,219</td></tr></table>

Question: What was the average of the 6.125% notes due April 2039 and 5.25% notes due November 2039 in the years where Long-term debt is positive?
Answer: 275