The following table presents consolidated revenues by our business models and by segment, as a percentage of total revenues:
## Table 0 ##
Health Care and Health Care IT Industry Health care expenditures continue to consume an increasing portion of most economies.
In the U. S. , health care spending increased 3.9 percent to $3.5 trillion in 2017, and now represents 17.9 percent of the U. S. ' Gross Domestic Product ("GDP").
An aging population and high levels of chronic conditions are contributing to expectations that health care expenditures will continue growing faster than the economy.
The Centers for Medicare and Medicaid Services ("CMS") estimates annual U. S.  health care spending will grow at an average rate of 5.5 percent through 2026 and reach $5.7 trillion, or 19.7 percent of GDP by 2026.
We believe this trajectory is unsustainable and that health care IT can play an important role in facilitating a shift from a high-cost health care system that incents volume to a proactive system that incents health, quality and efficiency.
For this change to occur, we believe traditional fee-for-service ("FFS") reimbursement models must continue to shift to valuebased approaches that are more aligned with quality, outcomes, and efficiency.
The shift away from traditional FFS is evident in growth of lives covered under Accountable Care Organizations ("ACOs").
ACOs are groups of hospitals and providers that focus on providing coordinated, high quality care to Medicare, Medicaid, or commercially insured populations and then share in savings created by lowering the cost of care.
According to Leavitt Partners, lives covered under ACOs grew from approximately 5 million in 2011 to more than 32 million in 2018.
In addition to the increasing number of lives covered under ACOs, the structure of ACOs is evolving to where providers are expected to assume more risk.
Currently, most ACO contracts are upside only, which means providers can receive bonuses for good performance, but they assume no downside for underperformance.
In 2018, CMS released a rule called "Pathways to Success" that accelerates the timeframe during which providers need to move to ACOs that include both upside bonuses and downside penalties.
We believe this shift is important as assumption of risk by providers creates a strong incentive for them to improve care coordination and deliver high quality care at a lower cost.
Another step towards a value-based model occurred with the passage of The Medicare Access and CHIP Reauthorization Act ("MACRA"), which enacts significant reforms to the payment programs under the Medicare Physician Fee Schedule and consolidated three current value-based programs into one.
While each of the different approaches to aligning reimbursement with value will continue to evolve, we believe the trend away from traditional FFS will continue.
We believe this growth in government and private models aligning payment with value, quality and outcomes will drive major changes in the way health care is provided in the next decade, and we expect a much greater focus on patient engagement, wellness and prevention.
As health care providers become accountable for proactively managing the health of the populations they serve, we expect them to need ongoing investment in sophisticated information technology solutions that will enable them to predict when intervention is needed so they can improve outcomes and lower the cost of providing care.
Backlog, which reflects contracted revenue that has not yet been recognized as revenue, was $15.25 billion as of December 29, 2018, of which we expect to recognize approximately 29% as revenue over the next 12 months.
In the first quarter of 2018, we adopted new revenue recognition guidance as further discussed in Note (2) of the notes to consolidated financial statements.
In connection with the adoption of such guidance, we modified our calculation of backlog as previously determined under Regulation S-K to represent the aggregate amount of transaction price allocated to performance obligations that are unsatisfied (or partially satisfied) to conform to the new revenue recognition guidance.
Backlog amounts disclosed prior to the adoption of the new revenue recognition guidance have not been adjusted, and are not comparable to, the current period presentation.
We believe that backlog may not necessarily be a comprehensive indicator of future revenue as certain of our arrangements may be canceled (or conversely renewed) at our clients' option, thus contract consideration related to such cancellable periods has been excluded from our calculation of backlog.
However, historically our experience has been that such cancellation provisions are rarely exercised.
We expect to recognize approximately $525 million of revenue over the next 12 months under currently executed contracts related to such cancellable periods, which is not included in our calculation of backlog.
Costs of Revenue Costs of revenue as a percent of revenues were 17% in both 2018 and 2017.
Costs of revenue include the cost of reimbursed travel expense, sales commissions, third party consulting services and subscription content and computer hardware, devices and sublicensed software purchased from manufacturers for delivery to clients.
It also includes the cost of hardware maintenance and sublicensed software support subcontracted to the manufacturers.
Such costs, as a percent of revenues, typically have varied as the mix of revenue (software, hardware, devices, maintenance, support, and services) carrying different margin rates changes from period to period.
Costs of revenue does not include the costs of our client service personnel who are responsible for delivering our service offerings.
Such costs are included in sales and client service expense.
Operating Expenses Total operating expenses increased 10% to $3.65 billion in 2018, as compared to $3.33 billion in 2017.  ?
Sales and client service expenses as a percent of revenues were 46% in 2018, compared to 44% in 2017.
These expenses increased 10% to $2.49 billion in 2018, from $2.28 billion in 2017.
Sales and client service expenses include salaries and benefits of sales, marketing, support, and services personnel, depreciation and other expenses associated with our managed services business, communications expenses, unreimbursed travel expenses, expense for share-based payments, and trade show and advertising costs.
The 2018 amount includes a pre-tax charge of $45 million to provide an allowance against certain client receivables with Fujitsu Services Limited ("Fujitsu"), as further discussed in Note (3) of the notes to consolidated financial statements.
The remaining growth in sales and client service expenses is primarily due to the hiring of services personnel to support growth in services revenue.  ?
Software development expenses as a percent of revenues were 13% in 2018, compared to 12% in 2017.
Expenditures for software development include ongoing development and enhancement of the Cerner Millennium?
and HealtheIntent platforms, with a focus on supporting key initiatives to enhance physician experience, revenue cycle and population health solutions.
A summary of our total software development expense in 2018 and 2017 is as follows:
## Table 1 ##
General and administrative expenses as a percent of revenues were 7% in both 2018 and 2017.
These expenses increased 10% to $389 million in 2018, from $355 million in 2017.
General and administrative expenses include
salaries and benefits for corporate, financial and administrative staffs, utilities, communications expenses, professional fees, depreciation and amortization, transaction gains or losses on foreign currency, expense for share-based payments, acquisition costs and related adjustments.
The increase in general and administrative expenses is primarily due to increased expense associated with share-based payment awards.  ?
Amortization of acquisition-related intangibles as a percent of revenues was 2% in both 2018 and 2017.
These expenses decreased 4% to $87 million in 2018, from $91 million in 2017.
Amortization of acquisition-related intangibles includes the amortization of customer relationships, acquired technology, trade names, and non- compete agreements recorded in connection with our business acquisitions.
The decrease in amortization of acquisition-related intangibles includes the impact of certain intangible assets becoming fully amortized.
Non-Operating Items ?
Other income, net was $26 million in 2018, compared to $7 million in 2017.
The increase is primarily attributable to increased interest on our cash and investment balances, due to rising interest rates.  ?
Our effective tax rate was 21% in 2018, compared to 10% in 2017.
The increase in the effective tax rate in 2018 is primarily a result of impacts from certain U. S.  income tax reform enacted in December 2017.
Refer to Note (12) of the notes to consolidated financial statements for further information regarding our effective tax rate.
We do not expect significant changes to our overall effective tax rate in 2019, from what is reported for 2018.
Operations by Segment We have two operating segments: Domestic and Global.
The Domestic segment includes revenue contributions and expenditures associated with business activity in the United States.
The Global segment primarily includes revenue contributions and expenditures linked to business activity in Aruba, Australia, Austria, the Bahamas, Belgium, Bermuda, Brazil, Canada, Cayman Islands, Chile, Denmark, Egypt, England, Finland, France, Germany, India, Ireland, Kuwait, Luxembourg, Malaysia, Mexico, Netherlands, Norway, Portugal, Qatar, Romania, Saudi Arabia, Singapore, Slovakia, Spain, Sweden, Switzerland and the United Arab Emirates.
Refer to Note (17) of the notes to consolidated financial statements for further information regarding our reportable segments.
The following table presents a summary of our operating segment information for the years ended 2018 and 2017:
## Table 2 ##
Domestic Segment ?
Revenues increased 3% to $4.73 billion in 2018, from $4.58 billion in 2017.
The growth in revenues includes a $181 million increase in professional services revenue, driven by increased contributions from Cerner ITWork
Valuation techniques – Cash equivalents are mostly comprised of short-term money-market instruments and are valued at cost, which approximates fair value.
U. S.  equity securities and international equity securities categorized as Level 1 are traded on active national and international exchanges and are valued at their closing prices on the last trading day of the year.
For U. S.  equity securities and international equity securities not traded on an active exchange, or if the closing price is not available, the trustee obtains indicative quotes from a pricing vendor, broker, or investment manager.
These securities are categorized as Level 2 if the custodian obtains corroborated quotes from a pricing vendor or categorized as Level 3 if the custodian obtains uncorroborated quotes from a broker or investment manager.
Commingled equity funds are public investment vehicles valued using the Net Asset Value (NAV) provided by the fund manager.
The NAV is the total value of the fund divided by the number of shares outstanding.
Commingled equity funds are categorized as Level 1 if traded at their NAV on a nationally recognized securities exchange or categorized as Level 2 if the NAV is corroborated by observable market data (e. g. , purchases or sales activity).
Fixed income securities categorized as Level 2 are valued by the trustee using pricing models that use verifiable observable market data (e. g.  interest rates and yield curves observable at commonly quoted intervals), bids provided by brokers or dealers, or quoted prices of securities with similar characteristics.
Private equity funds, real estate funds, hedge funds, and fixed income securities categorized as Level 3 are valued based on valuation models that include significant unobservable inputs and cannot be corroborated using verifiable observable market data.
Valuations for private equity funds and real estate funds are determined by the general partners, while hedge funds are valued by independent administrators.
Depending on the nature of the assets, the general partners or independent administrators use both the income and market approaches in their models.
The market approach consists of analyzing market transactions for comparable assets while the income approach uses earnings or the net present value of estimated future cash flows adjusted for liquidity and other risk factors.
Commodities categorized as Level 1 are traded on an active commodity exchange and are valued at their closing prices on the last trading day of the year.
Commodities categorized as Level 2 represent shares in a commingled commodity fund valued using the NAV, which is corroborated by observable market data.
Contributions and Expected Benefit Payments We generally determine funding requirements for our defined benefit pension plans in a manner consistent with CAS and Internal Revenue Code rules.
In 2012, we made contributions of $3.6 billion related to our qualified defined benefit pension plans.
We plan to make contributions of approximately $1.5 billion related to the qualified defined benefit pension plans in 2013.
In 2012, we made contributions of $235 million related to our retiree medical and life insurance plans.
We expect no required contributions related to the retiree medical and life insurance plans in 2013.
The following table presents estimated future benefit payments, which reflect expected future employee service, as of December 31, 2012 (in millions):

<table><tr><td></td><td colspan="3">For the Years Ended</td></tr><tr><td></td><td>2018</td><td>2017</td><td>2016</td></tr><tr><td>Revenues by Business Models</td><td></td><td></td><td></td></tr><tr><td>Licensed software</td><td>11%</td><td>12%</td><td>11%</td></tr><tr><td>Technology resale</td><td>5%</td><td>5%</td><td>6%</td></tr><tr><td>Subscriptions</td><td>6%</td><td>9%</td><td>9%</td></tr><tr><td>Professional services</td><td>34%</td><td>31%</td><td>30%</td></tr><tr><td>Managed services</td><td>21%</td><td>21%</td><td>21%</td></tr><tr><td>Support and maintenance</td><td>21%</td><td>20%</td><td>21%</td></tr><tr><td>Reimbursed travel</td><td>2%</td><td>2%</td><td>2%</td></tr><tr><td></td><td>100%</td><td>100%</td><td>100%</td></tr><tr><td>Revenues by Segment</td><td></td><td></td><td></td></tr><tr><td>Domestic</td><td>88%</td><td>89%</td><td>89%</td></tr><tr><td>Global</td><td>12%</td><td>11%</td><td>11%</td></tr><tr><td></td><td>100%</td><td>100%</td><td>100%</td></tr></table>
<table><tr><td></td><td colspan="2">For the Years Ended</td></tr><tr><td>(In thousands)</td><td>2018</td><td>2017</td></tr><tr><td>Software development costs</td><td>$747,128</td><td>$705,944</td></tr><tr><td>Capitalized software costs</td><td>-271,787</td><td>-271,411</td></tr><tr><td>Capitalized costs related to share-based payments</td><td>-1,906</td><td>-2,737</td></tr><tr><td>Amortization of capitalized software costs</td><td>210,228</td><td>173,250</td></tr><tr><td>Total software development expense</td><td>$683,663</td><td>$605,046</td></tr></table>
<table><tr><td>(In thousands)</td><td>2018</td><td>% of Segment Revenue</td><td>2017</td><td>% of Segment Revenue</td><td>% Change</td></tr><tr><td>Domestic Segment</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Revenues</td><td>$4,730,266</td><td>100%</td><td>$4,575,171</td><td>100%</td><td>3%</td></tr><tr><td>Costs of revenue</td><td>827,904</td><td>18%</td><td>755,729</td><td>17%</td><td>10%</td></tr><tr><td>Operating expenses</td><td>2,164,465</td><td>46%</td><td>1,998,544</td><td>44%</td><td>8%</td></tr><tr><td>Total costs and expenses</td><td>2,992,369</td><td>63%</td><td>2,754,273</td><td>60%</td><td>9%</td></tr><tr><td>Domestic operating earnings</td><td>1,737,897</td><td>37%</td><td>1,820,898</td><td>40%</td><td>-5%</td></tr><tr><td>Global Segment</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Revenues</td><td>636,059</td><td>100%</td><td>567,101</td><td>100%</td><td>12%</td></tr><tr><td>Costs of revenue</td><td>109,444</td><td>17%</td><td>98,362</td><td>17%</td><td>11%</td></tr><tr><td>Operating expenses</td><td>321,116</td><td>50%</td><td>264,196</td><td>47%</td><td>22%</td></tr><tr><td>Total costs and expenses</td><td>430,560</td><td>68%</td><td>362,558</td><td>64%</td><td>19%</td></tr><tr><td>Global operating earnings</td><td>205,499</td><td>32%</td><td>204,543</td><td>36%</td><td>—%</td></tr><tr><td>Other, net</td><td>-1,168,611</td><td></td><td>-1,064,970</td><td></td><td>10%</td></tr><tr><td>Consolidated operating earnings</td><td>$774,785</td><td></td><td>$960,471</td><td></td><td>-19%</td></tr></table>

Question: what is the expected percentage change in contributions related to qualified defined benefit pension plans in 2013 compare to 2012?
Answer: -0.58333