Table of Contents 16 Other Equity Method Investments InfraServs.
We hold indirect ownership interests in several German InfraServ Groups that own and develop industrial parks and provide on-site general and administrative support to tenants.
Our ownership interest in the equity investments in InfraServ affiliates are as follows:
||As of December 31, 2017 (In percentages)|
|InfraServ GmbH & Co. Gendorf KG-1|39|
|InfraServ GmbH & Co. Hoechst KG|32|
|InfraServ GmbH & Co. Knapsack KG-1|27|

(1) See Note 29 - Subsequent Events in the accompanying consolidated financial statements for further information.
Research and Development Our business models leverage innovation and conduct research and development activities to develop new, and optimize existing, production technologies, as well as to develop commercially viable new products and applications.
Research and development expense was $72 million, $78 million and $119 million for the years ended December 31, 2017, 2016 and 2015, respectively.
We consider the amounts spent during each of the last three fiscal years on research and development activities to be sufficient to execute our current strategic initiatives.
Intellectual Property We attach importance to protecting our intellectual property, including safeguarding our confidential information and through our patents, trademarks and copyrights, in order to preserve our investment in research and development, manufacturing and marketing.
Patents may cover processes, equipment, products, intermediate products and product uses.
We also seek to register trademarks as a means of protecting the brand names of our Company and products.
Patents.
In most industrial countries, patent protection exists for new substances and formulations, as well as for certain unique applications and production processes.
However, we do business in regions of the world where intellectual property protection may be limited and difficult to enforce.
Confidential Information.
We maintain stringent information security policies and procedures wherever we do business.
Such information security policies and procedures include data encryption, controls over the disclosure and safekeeping of confidential information and trade secrets, as well as employee awareness training.
Trademarks.
Amcel?
, AOPlus?
, Ateva?
, Avicor?
, Celanese?
, Celanex?
, Celcon?
, CelFX?
, Celstran?
, Celvolit?
, Clarifoil?
, DurO-Set?
, Ecomid?
, EcoVAE?
, Forflex?
, Forprene?
, FRIANYL?
, Fortron?
, GHR?
, Gumfit?
, GUR?
, Hostaform?
, Laprene?
, MetaLX?
, Mowilith?
, MT?
, NILAMID?
, Nivionplast?
, Nutrinova?
, Nylfor?
, Pibiflex?
, Pibifor?
, Pibiter?
, Polifor?
, Resyn?
, Riteflex?
, SlideX?
, Sofprene?
, Sofpur?
, Sunett?
, Talcoprene?
, Tecnoprene?
, Thermx?
, TufCOR?
, VAntage?
, Vectra?
, Vinac?
, Vinamul?
, VitalDose?
, Zenite?
and certain other branded products and services named in this document are registered or reserved trademarks or service marks owned or licensed by Celanese.
The foregoing is not intended to be an exhaustive or comprehensive list of all registered or reserved trademarks and service marks owned or licensed by Celanese.
Fortron?
is a registered trademark of Fortron Industries LLC.
Hostaform?
is a registered trademark of Hoechst GmbH.
Mowilith?
and NILAMID?
are registered trademarks of Celanese in most European countries.
We monitor competitive developments and defend against infringements on our intellectual property rights.
Neither Celanese nor any particular business segment is materially dependent upon any one patent, trademark, copyright or trade secret.
Environmental and Other Regulation Matters pertaining to environmental and other regulations are discussed in Item 1A.
Risk Factors, as well as Note 2 - Summary of Accounting Policies, Note 16 - Environmental and Note 24 - Commitments and Contingencies in the accompanying consolidated financial statements.
NOTE 7 - BANK LOANS, NET: Bank client receivables are comprised of loans originated or purchased by RJ Bank and include commercial and residential real estate loans, as well as commercial and consumer loans.
These receivables are collateralized by first or second mortgages on residential or other real property, by other assets of the borrower or are unsecured.
The following table presents the balance and associated percentage of each major loan category in RJ Bank's portfolio, including loans receivable and loans available for sale:
||September 30, 2009|September 30, 2008|September 30, 2007|September 30, 2006|September 30, 2005|
||Balance%||Balance%||Balance%||Balance%||Balance%||
||($ in 000’s)|
|Commercial|||||||||||
|Loans|$ 851,657|13%|$ 725,997|10%|$ 343,783|7%|$ 272,957|12%|$ 144,254|14%|
|Real Estate|||||||||||
|Construction|||||||||||
|Loans|163,951|3%|346,691|5%|123,664|3%|34,325|2%|32,563|3%|
|Commercial|||||||||||
|Real Estate|||||||||||
|Loans -1|3,343,989|49%|3,528,732|49%|2,317,840|49%|653,695|28%|136,375|14%|
|Residential|||||||||||
|Mortgage|||||||||||
|Loans|2,398,822|35%|2,599,567|36%|1,934,645|41%|1,322,908|58%|690,242|69%|
|Consumer|||||||||||
|Loans|22,816|-|23,778|-|4,541|-|1,917|-|2,752|-|
|Total Loans|6,781,235|100%|7,224,765|100%|4,724,473|100%|2,285,802|100%|1,006,186|100%|
|Net Unearned|||||||||||
|Income and|||||||||||
|Deferred|||||||||||
|Expenses -2|-36,990||-41,383||-13,242||-4,276||1,688||
|Allowance for|||||||||||
|Loan Losses|-150,272||-88,155||-47,022||-18,694||-7,593||
||-187,262||-129,538||-60,264||-22,970||-5,905||
|Loans, Net|$6,593,973||$7,095,227||$ 4,664,209||$ 2,262,832||$ 1,000,281||

(1) Of this amount, $1.2 billion, $1.2 billion, $687 million, $393 million and $137 million is secured by non-owner occupied commercial real estate properties or their repayment is dependent upon the operation or sale of commercial real estate properties as of September 30, 2009, 2008, 2007, 2006 and 2005, respectively.
The remainder is wholly or partially secured by real estate, the majority of which is also secured by other assets of the borrower.
(2) Includes purchase premiums, purchase discounts, and net deferred origination fees and costs.
At September 30, 2009 and September 30, 2008, RJ Bank had $950 million and $1.7 billion, respectively, in FHLB advances secured by a blanket lien on RJ Bank's residential mortgage loan portfolio.
See Note 11 for more information regarding the FHLB advances.
At September 30, 2009 and 2008, RJ Bank had $40.5 million and $524,000 in loans held for sale, respectively.
RJ Bank's gain from the sale of these loans held for sale was $676,000, $364,000 and $518,000 for the years ended September 30, 2009, 2008 and 2007, respectively
business conducted annually with each institution.
Fixed income commissions are based on trade size and the characteristics of the specific security involved.
Capital Markets Commissions For the Fiscal Years Ended:
||September 30, 2009|% of Total|September 30, 2008|% of Total|September 30, 2007|% of Total|
||($ in 000's)|
|Equity|$ 212,322|57%|$ 237,920|70%|$ 210,343|83%|
|Fixed Income|160,211|43%|99,870|30%|44,454|17%|
|Total Commissions|$ 372,533|100%|$ 337,790|100%|$ 254,797|100%|

Approximately 100 domestic and overseas professionals in RJ&A's Institutional Equity Sales and Sales Trading Departments maintain relationships with over 1,190 institutional clients, principally in North America and Europe.
In addition to our headquarters in St.  Petersburg, Florida, RJ&A has institutional equity sales offices in New York City, Boston, Chicago, Los Angeles, San Francisco, London, Geneva, Brussels, Dusseldorf, Luxembourg and Paris.
European offices also provide services to high net worth clients.
RJ Ltd.  has 33 institutional equity sales and trading professionals servicing predominantly Canadian institutional investors from offices in Montreal, Toronto and Vancouver.
RJ&A distributes to institutional clients both taxable and tax-exempt fixed income products, primarily municipal, corporate, government agency and mortgage-backed bonds.
RJ&A carries inventory positions of taxable and tax-exempt securities in both the primary and secondary markets to facilitate institutional sales activities.
In addition to St.  Petersburg, the Fixed Income Department maintains institutional sales and trading offices in New York City, Chicago and 20 other cities throughout the U. S.  Trading Trading equity securities involves the purchase and sale of securities from/to our clients or other dealers.
Profits and losses are derived from the spreads between bid and asked prices, as well as market trends for the individual securities during the period we hold them.
RJ&A makes markets in approximately 680 common stocks.
Similar to the equity research department, this operation serves to support both our Institutional and Private Client Group sales efforts.
The RJ Ltd.  Institutional and Private Client Group trading desks not only support client activity, but also take proprietary positions.
RJ Ltd.  also provides specialist services in approximately 160 TSX listed common stocks.
RJ&A trades both taxable and tax-exempt fixed income products.
The taxable and tax-exempt RJ&A fixed income traders purchase and sell corporate, municipal, government, government agency, and mortgage-backed bonds, asset backed securities, preferred stock and certificates of deposit from/to our clients or other dealers.
RJ&A enters into future commitments such as forward contracts and “to be announced” securities (e. g.  securities having a stated coupon and original term to maturity, although the issuer and/or the specific pool of mortgage loans is not known at the time of the transaction).
Low levels of proprietary trading positions are also periodically taken by RJ&A for various purposes and are closely monitored within well defined limits.
In addition, a subsidiary of RJF, RJ Capital Services Inc. , participates in the interest rate swaps market as a principal, both for economically hedging RJ&A fixed income inventory and for transactions with customers.
Equity Research The domestic senior analysts in RJ&A's research department support our institutional and retail sales efforts and publish research on approximately 725 companies.
This research primarily focuses on U. S.  companies in specific industries including technology, telecommunications, consumer, financial services, business and industrial services, healthcare, real estate and energy.
Proprietary industry studies and company-specific research reports are made available to both institutional and individual clients.
RJ Ltd.  has an additional 16 analysts who publish research on approximately 200 companies focused in the energy, energy services, mining, forest products, biotechnology, technology, clean technology, consumer and industrial products, REIT and income trust sectors.
These analysts, combined with 12 additional analysts located in France (whose services are obtained through a joint venture there), represent our global research effort within the Capital Markets segment.
The following table shows the distribution of those RJ Bank loans that mature in more than one year between fixed and adjustable interest rate loans at September 30, 2009:

Question: what is the percentage change in research and development expense from 2015 to 2016?

Python solution:
def solution():
    # Define variables name and value
    r_and_d_expense_2015 = 119
    r_and_d_expense_2016 = 78

    # Do math calculation to get the answer
    difference = r_and_d_expense_2016 - r_and_d_expense_2015
    percentage_change = (difference / r_and_d_expense_2015) * 100

    return percentage_change

Answer: -34.4537815126