research and development we are committed to investing in highly productive research and development capabilities , particularly in electro-mechanical systems .
our research and development ( "r&d" ) expenditures were approximately $ 48.3 million , $ 47.3 million and $ 45.2 million for the years ended december 31 , 2017 , 2016 and 2015 , respectively .
we concentrate on developing technology innovations that will deliver growth through the introduction of new products and solutions , and also on driving continuous improvements in product cost , quality , safety and sustainability .
we manage our r&d team as a global group with an emphasis on a global collaborative approach to identify and develop new technologies and worldwide product platforms .
we are organized on a regional basis to leverage expertise in local standards and configurations .
in addition to regional engineering centers in each geographic region , we also operate a global engineering center of excellence in bangalore , india .
seasonality our business experiences seasonality that varies by product line .
because more construction and do-it-yourself projects occur during the second and third calendar quarters of each year in the northern hemisphere , our security product sales , typically , are higher in those quarters than in the first and fourth calendar quarters .
however , our interflex business typically experiences higher sales in the fourth calendar quarter due to project timing .
revenue by quarter for the years ended december 31 , 2017 , 2016 and 2015 are as follows: .

First Quarter
Second Quarter
Third Quarter
Fourth Quarter
2017
23%
26%
25%
26%
2016
22%
26%
26%
26%
2015
22%
25%
26%
27%

employees we currently have approximately 10000 employees .
environmental regulation we have a dedicated environmental program that is designed to reduce the utilization and generation of hazardous materials during the manufacturing process as well as to remediate identified environmental concerns .
as to the latter , we are currently engaged in site investigations and remediation activities to address environmental cleanup from past operations at current and former production facilities .
the company regularly evaluates its remediation programs and considers alternative remediation methods that are in addition to , or in replacement of , those currently utilized by the company based upon enhanced technology and regulatory changes .
we are sometimes a party to environmental lawsuits and claims and have received notices of potential violations of environmental laws and regulations from the u.s .
environmental protection agency ( the "epa" ) and similar state authorities .
we have also been identified as a potentially responsible party ( "prp" ) for cleanup costs associated with off-site waste disposal at federal superfund and state remediation sites .
for all such sites , there are other prps and , in most instances , our involvement is minimal .
in estimating our liability , we have assumed that we will not bear the entire cost of remediation of any site to the exclusion of other prps who may be jointly and severally liable .
the ability of other prps to participate has been taken into account , based on our understanding of the parties 2019 financial condition and probable contributions on a per site basis .
additional lawsuits and claims involving environmental matters are likely to arise from time to time in the future .
we incurred $ 3.2 million , $ 23.3 million , and $ 4.4 million of expenses during the years ended december 31 , 2017 , 2016 , and 2015 , respectively , for environmental remediation at sites presently or formerly owned or leased by us .
as of december 31 , 2017 and 2016 , we have recorded reserves for environmental matters of $ 28.9 million and $ 30.6 million .
of these amounts $ 8.9 million and $ 9.6 million , respectively , relate to remediation of sites previously disposed by us .
given the evolving nature of environmental laws , regulations and technology , the ultimate cost of future compliance is uncertain. .

Question: Analyse this data from a financial earnings document. considering the years 2016-2017 , what is the increase observed in the research and development expenditures?
Choices:
0.02114
45.17886
-8.57886
2.02114
-29.57886
Correct choice index: 0