Notes to Consolidated Financial Statements – (continued) (Amounts in Millions, Except Per Share Amounts) During 2017, we completed ten acquisitions, eight of which were included in the Integrated Agency Networks (“IAN”) operating segment, and two of which were included in the Constituency Management Group (“CMG”) operating segment.
These acquisitions included a digital marketing agency based in the U. S. , a data science and business intelligence firm based in the U. S.  with operations in China, an advertising and consulting company based in Indonesia, a strategic communications agency based in the U. K. , an independent creative agency based in the U. K. , a retail branding and design firm based in the U. S. , a content creation and marketing agency based in the Netherlands, an independent media agency and digital consultancy based in Finland, and an integrated marketing communications agency based in Canada.
During 2017, we recorded approximately $62.0 of goodwill and intangible assets related to our acquisitions.
During 2016, we completed ten acquisitions, three of which were included in the IAN operating segment, and seven of which were included in the CMG operating segment.
The most significant acquisitions included a product and service design consultancy based in the U. S. , an integrated healthcare marketing communications agency based in the U. S. , a content creation and digital agency with offices in the U. S.  and the U. K. , a mobile consultancy and application development agency based in the U. K. , a full-service public relations and digital agency based in China, a search engine optimization and digital content marketing agency based in the U. K. , and a mobile focused digital agency based in the U. K.  During 2016, we recorded approximately $149.0 of goodwill and intangible assets related to these acquisitions.
During 2015, we completed five acquisitions, four of which were included in the IAN operating segment, and one of which was included in the CMG operating segment.
The most significant acquisitions included a full-service digital agency in the U. K. , a group of creative marketing agencies based in Russia, and a media planning and buying agency with significant digital capabilities in Canada.
During 2015, we recorded approximately $61.0 of goodwill and intangible assets related to these acquisitions.
The results of operations of our acquired companies were included in our consolidated results from the closing date of each acquisition.
We did not make any payments in stock related to our acquisitions in 2017, 2016 or 2015.
Details of cash paid for current and prior years’ acquisitions are listed below.
## Table 0 ##
1 Represents cash payments for amounts that have been recognized in operating expenses since the date of acquisition either relating to adjustments to estimates in excess of the initial value of contingent payments recorded or were contingent upon the future employment of the former owners of the acquired companies.
Amounts are reflected in the operating section of the Consolidated Statements of Cash Flows.2 Of the total cash paid for acquisitions, $30.6, $52.0 and $28.6 for the years ended December 31, 2017, 2016 and 2015, respectively, are classified under the investing section of the Consolidated Statements of Cash Flows as acquisitions, net of cash acquired.
These amounts relate to initial payments for new transactions.
Of the total cash paid for acquisitions, $53.7, $40.8 and $53.1 for the years ended December 31, 2017, 2016 and 2015, respectively, are classified under the financing section of the Consolidated Statements of Cash Flows as acquisition-related payments.
These amounts relate to deferred payments and increases in our ownership interest for prior acquisitions.
For companies acquired, we estimate the fair values of the assets and liabilities based on 100% of the business for consolidation.
The purchase price in excess of the estimated fair value of the tangible net assets acquired is allocated to identifiable intangible assets and then to goodwill.
Due to the characteristics of advertising, specialized marketing and communication services companies, our acquisitions typically do not have significant amounts of tangible assets since the principal assets we acquire are client relationships and talent.
As a result, a substantial portion of the purchase price is primarily allocated to customer lists, trade names and goodwill.
Notes to Consolidated Financial Statements – (continued) (Amounts in Millions, Except Per Share Amounts) Guarantees We have guaranteed certain obligations of our subsidiaries relating principally to operating leases and uncommitted lines of credit of certain subsidiaries.
The amount of parent company guarantees on lease obligations was $829.2 and $857.3 as of December 31, 2017 and 2016, respectively, and the amount of parent company guarantees primarily relating to uncommitted lines of credit was $491.0 and $395.6 as of December 31, 2017 and 2016, respectively.
In the event of non-payment by the applicable subsidiary of the obligations covered by a guarantee, we would be obligated to pay the amounts covered by that guarantee.
As of December 31, 2017, there were no material assets pledged as security for such parent company guarantees.
Contingent Acquisition Obligations The following table details the estimated future contingent acquisition obligations payable in cash as of December 31, 2017.
## Table 1 ##
1 We have entered into certain acquisitions that contain both redeemable noncontrolling interests and call options with similar terms and conditions.
The estimated amounts listed would be paid in the event of exercise at the earliest exercise date.
We have certain redeemable noncontrolling interests that are exercisable at the discretion of the noncontrolling equity owners as of December 31, 2017.
These estimated payments of $24.8 are included within the total payments expected to be made in 2018, and will continue to be carried forward into 2019 or beyond until exercised or expired.
Redeemable noncontrolling interests are included in the table at current exercise price payable in cash, not at applicable redemption value, in accordance with the authoritative guidance for classification and measurement of redeemable securities.
The majority of these payments are contingent upon achieving projected operating performance targets and satisfying other conditions specified in the related agreements and are subject to revision in accordance with the terms of the respective agreements.
See Note 4 for further information relating to the payment structure of our acquisitions.
Legal Matters In the normal course of business, we are involved in various legal proceedings, and subject to investigations, inspections, audits, inquiries and similar actions by governmental authorities.
The types of allegations that arise in connection with such legal proceedings vary in nature, but can include claims related to contract, employment, tax and intellectual property matters.
We evaluate all cases each reporting period and record liabilities for losses from legal proceedings when we determine that it is probable that the outcome in a legal proceeding will be unfavorable and the amount, or potential range, of loss can be reasonably estimated.
In certain cases, we cannot reasonably estimate the potential loss because, for example, the litigation is in its early stages.
While any outcome related to litigation or such governmental proceedings in which we are involved cannot be predicted with certainty, management believes that the outcome of these matters, individually and in the aggregate, will not have a material adverse effect on our financial condition, results of operations or cash flows.
As previously disclosed, on April 10, 2015, a federal judge in Brazil authorized the search of the records of an agency’s offices in S?o Paulo and Brasilia, in connection with an ongoing investigation by Brazilian authorities involving payments potentially connected to local government contracts.
The Company had previously investigated the matter and taken a number of remedial and disciplinary actions.
The Company is in the process of concluding a settlement related to these matters with government agencies.
The Company confirmed that one of its standalone domestic agencies has been contacted by the Department of Justice Antitrust Division for documents regarding video production practices and is cooperating with the government.
Notes to Consolidated Financial Statements – (continued) (Amounts in Millions, Except Per Share Amounts) Assumption
## Table 2 ##
Discount Rates – At December 31, 2018, 2017 and 2016, we determined our discount rates for our domestic pension plan, foreign pension plans and domestic postretirement benefit plan based on either a bond selection/settlement approach or bond yield curve approach.
Using the bond selection/settlement approach, we determine the discount rate by selecting a portfolio of corporate bonds appropriate to provide for the projected benefit payments.
Using the bond yield curve approach, we determine the discount rate by matching the plans’ cash flows to spot rates developed from a yield curve.
Both approaches utilize high-quality AA-rated corporate bonds and the plans’ projected cash flows to develop a discounted value of the benefit payments, which is then used to develop a single discount rate.
In countries where markets for high-quality long-term AA corporate bonds are not well developed, a portfolio of long-term government bonds is used as a basis to develop hypothetical corporate bond yields, which serve as a basis to derive the discount rate.
Expected Return on Assets – Our expected rate of return is determined at the beginning of each year and considers asset class index returns over various market and economic conditions, current and expected market conditions, risk premiums associated with asset classes and long-term inflation rates.
We determine both a short-term and long-term view and then select a long-term rate of return assumption that matches the duration of our liabilities.
Fair Value of Pension Plan Assets The following table presents the fair value of our domestic and foreign pension plan assets as of December 31, 2018 and 2017, and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value.
See Note 12 for a description of the fair value hierarch
## Table 3 ##
1 Certain investments that are measured at fair value using the net asset value per share (or its equivalent) as a practical expedient have not been classified in the fair value hierarchy but are included to reconcile to the amounts presented in the fair value of plan assets table above

<table><tr><td></td><td colspan="3">Years ended December 31,</td></tr><tr><td></td><td>2017</td><td>2016</td><td>2015</td></tr><tr><td>Cost of investment: current-year acquisitions</td><td>$36.8</td><td>$65.7</td><td>$37.8</td></tr><tr><td>Cost of investment: prior-year acquisitions</td><td>54.6</td><td>40.7</td><td>53.1</td></tr><tr><td>Less: net cash acquired</td><td>-7.1</td><td>-13.6</td><td>-9.2</td></tr><tr><td>Total cost of investment</td><td>84.3</td><td>92.8</td><td>81.7</td></tr><tr><td>Operating payments<sup>1</sup></td><td>47.1</td><td>19.1</td><td>18.4</td></tr><tr><td>Total cash paid for acquisitions<sup>2</sup></td><td>$131.4</td><td>$111.9</td><td>$100.1</td></tr></table>
<table><tr><td></td><td>2018</td><td>2019</td><td>2020</td><td>2021</td><td>2022</td><td>Thereafter</td><td>Total</td></tr><tr><td>Deferred acquisition payments</td><td>$41.9</td><td>$27.5</td><td>$16.1</td><td>$24.4</td><td>$4.8</td><td>$6.3</td><td>$121.0</td></tr><tr><td>Redeemable noncontrolling interests and call options with affiliates<sup>1</sup></td><td>37.1</td><td>26.4</td><td>62.9</td><td>10.3</td><td>6.6</td><td>4.1</td><td>147.4</td></tr><tr><td>Total contingent acquisition payments</td><td>$79.0</td><td>$53.9</td><td>$79.0</td><td>$34.7</td><td>$11.4</td><td>$10.4</td><td>$268.4</td></tr></table>
<table><tr><td></td><td colspan="3">Domestic Pension Plan</td><td colspan="3">Foreign Pension Plans</td><td colspan="3">Domestic Postretirement Benefit Plan</td></tr><tr><td>Years ended December 31,</td><td>2018</td><td>2017</td><td>2016</td><td>2018</td><td>2017</td><td>2016</td><td>2018</td><td>2017</td><td>2016</td></tr><tr><td>Net periodic cost</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Discount rate</td><td>3.70%</td><td>4.20%</td><td>4.80%</td><td>2.36%</td><td>2.52%</td><td>3.61%</td><td>3.65%</td><td>4.05%</td><td>4.65%</td></tr><tr><td>Rate of compensation increase</td><td>N/A</td><td>N/A</td><td>N/A</td><td>2.37%</td><td>2.36%</td><td>3.18%</td><td>N/A</td><td>N/A</td><td>N/A</td></tr><tr><td>Expected return on plan assets</td><td>7.00%</td><td>7.00%</td><td>7.00%</td><td>4.70%</td><td>4.66%</td><td>5.38%</td><td>N/A</td><td>N/A</td><td>N/A</td></tr><tr><td>Interest crediting rates</td><td>5.10%</td><td>5.10%</td><td>5.10%</td><td>1.31%</td><td>1.29%</td><td>1.35%</td><td>N/A</td><td>N/A</td><td>N/A</td></tr><tr><td>Benefit obligation</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Discount rate</td><td>4.35%</td><td>3.70%</td><td>4.20%</td><td>2.61%</td><td>2.36%</td><td>2.52%</td><td>4.30%</td><td>3.65%</td><td>4.05%</td></tr><tr><td>Rate of compensation increase</td><td>N/A</td><td>N/A</td><td>N/A</td><td>2.58%</td><td>2.37%</td><td>2.36%</td><td>N/A</td><td>N/A</td><td>N/A</td></tr><tr><td>Interest crediting rates</td><td>5.10%</td><td>5.10%</td><td>5.10%</td><td>1.44%</td><td>1.31%</td><td>1.29%</td><td>N/A</td><td>N/A</td><td>N/A</td></tr><tr><td colspan="3">Health care cost trend rate assumed for next year</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Initial rate (weighted-average)</td><td></td><td></td><td></td><td></td><td></td><td></td><td>6.25%</td><td>6.50%</td><td>6.75%</td></tr><tr><td>Year ultimate rate is reached</td><td></td><td></td><td></td><td></td><td></td><td></td><td>2024</td><td>2024</td><td>2024</td></tr><tr><td>Ultimate rate</td><td></td><td></td><td></td><td></td><td></td><td></td><td>5.00%</td><td>5.00%</td><td>5.00%</td></tr></table>
<table><tr><td></td><td colspan="4">December 31, 2018</td><td colspan="4">December 31, 2017</td></tr><tr><td>Plan assets subject to fair value hierarchy</td><td>Level 1</td><td>Level 2</td><td>Level 3</td><td>Total</td><td>Level 1</td><td>Level 2</td><td>Level 3</td><td>Total</td></tr><tr><td>Registered investment companies</td><td>$13.0</td><td>$0.0</td><td>$0.0</td><td>$13.0</td><td>$14.7</td><td>$0.0</td><td>$0.0</td><td>$14.7</td></tr><tr><td>Limited partnerships</td><td>0.0</td><td>0.0</td><td>25.6</td><td>25.6</td><td>0.0</td><td>0.0</td><td>29.5</td><td>29.5</td></tr><tr><td>Fixed income securities</td><td>23.1</td><td>0.0</td><td>0.0</td><td>23.1</td><td>23.4</td><td>0.0</td><td>0.0</td><td>23.4</td></tr><tr><td>Insurance contracts</td><td>0.0</td><td>5.8</td><td>0.0</td><td>5.8</td><td>0.0</td><td>7.9</td><td>0.0</td><td>7.9</td></tr><tr><td>Other</td><td>20.0</td><td>0.0</td><td>0.0</td><td>20.0</td><td>27.7</td><td>0.0</td><td>0.0</td><td>27.7</td></tr><tr><td>Total plan assets, subject to leveling</td><td>$56.1</td><td>$5.8</td><td>$25.6</td><td>$87.5</td><td>$65.8</td><td>$7.9</td><td>$29.5</td><td>$103.2</td></tr><tr><td>Plan assets measured at net asset value</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Other investments measured at net asset value<sup>1</sup></td><td></td><td></td><td></td><td>366.2</td><td></td><td></td><td></td><td>399.8</td></tr><tr><td>Total plan assets</td><td></td><td></td><td></td><td>$453.7</td><td></td><td></td><td></td><td>$503.0</td></tr></table>

Question: what is the mathematical range of deferred acquisition payments from 2018-2022 , in millions?
Answer: 37.1