human
backlog applied manufactures systems to meet demand represented by order backlog and customer commitments. backlog consists of: (1) orders for which written authorizations have been accepted and assigned shipment dates are within the next 12 months, or shipment has occurred but revenue has not been recognized; and (2) contractual service revenue and maintenance fees to be earned within the next 12 months. backlog by reportable segment as of october 25, 2015 and october 26, 2014 was as follows: 2015 2014 (in millions, except percentages).
|  | 2015 | 2014 |  | (In millions, except percentages) |
| --------- | --------- | --------- | --------- | --------- |
| Silicon Systems | $1,720 | 55% | $1,400 | 48% |
| Applied Global Services | 812 | 26% | 775 | 27% |
| Display | 525 | 16% | 593 | 20% |
| Energy and Environmental Solutions | 85 | 3% | 149 | 5% |
| Total | $3,142 | 100% | $2,917 | 100% |
applied 2019s backlog on any particular date is not necessarily indicative of actual sales for any future periods, due to the potential for customer changes in delivery schedules or order cancellations. customers may delay delivery of products or cancel orders prior to shipment, subject to possible cancellation penalties. delays in delivery schedules or a reduction of backlog during any particular period could have a material adverse effect on applied 2019s business and results of operations. manufacturing, raw materials and supplies applied 2019s manufacturing activities consist primarily of assembly, test and integration of various proprietary and commercial parts, components and subassemblies that are used to manufacture systems. applied has implemented a distributed manufacturing model under which manufacturing and supply chain activities are conducted in various countries, including germany, israel, italy, singapore, taiwan, the united states and other countries in asia. applied uses numerous vendors, including contract manufacturers, to supply parts and assembly services for the manufacture and support of its products, including some systems being completed at customer sites. although applied makes reasonable efforts to assure that parts are available from multiple qualified suppliers, this is not always possible. accordingly, some key parts may be obtained from only a single supplier or a limited group of suppliers. applied seeks to reduce costs and to lower the risks of manufacturing and service interruptions by selecting and qualifying alternate suppliers for key parts; monitoring the financial condition of key suppliers; maintaining appropriate inventories of key parts; qualifying new parts on a timely basis; and ensuring quality and performance of parts. .
Please compute the result.
what was the silicon systems revenue for 2015?
assistant
1720.0
human
and for 2014?
assistant
1400.0
human
so what was the difference between these two years?
assistant
320.0
human
so what was the growth rate for this segment during this time?
assistant
0.22857