performance and revenue growth depends , in part , on the reliability and functionality of this infrastructure as a means of delivering human resources services .the internet is a key mechanism for delivering our human resources services to our hr solutions clients efficiently and cost effectively .our clients may not be receptive to human resource services delivered over the internet due to concerns regarding transaction security , user privacy , the reliability and quality of internet service and other reasons .our clients 2019 concerns may be heightened by the fact we use the internet to transmit extremely confidential information about our clients and their employees , such as compensation , medical information and other personally identifiable information .in order to maintain the level of security , service and reliability that our clients require , we may be required to make significant investments in our online methods of delivering human resources services .in addition , websites and proprietary online services have experienced service interruptions and other delays occurring throughout their infrastructure .the adoption of additional laws or regulations with respect to the internet may impede the efficiency of the internet as a medium of exchange of information and decrease the demand for our services .if we cannot use the internet effectively to deliver our services , our revenue growth and results of operation may be impaired .we may lose client data as a result of major catastrophes and other similar problems that may materially adversely impact our operations .we have multiple processing centers around the world that use various commercial methods for disaster recovery capabilities .our main data processing center is located near the aon hewitt headquarters in lincolnshire , illinois .in the event of a disaster , our business continuity may not be sufficient , and the data recovered may not be sufficient for the administration of our clients 2019 human resources programs and processes .item 1b .unresolved staff comments .item 2 .properties .we have offices in various locations throughout the world .substantially all of our offices are located in leased premises .we maintain our corporate headquarters at 200 e .randolph street in chicago , illinois , where we occupy approximately 327000 square feet of space under an operating lease agreement that expires in 2013 .there are two five-year renewal options at current market rates .we own one building at pallbergweg 2-4 , amsterdam , the netherlands ( 150000 square feet ) .the following are additional significant leased properties , along with the occupied square footage and expiration. .
[['property:', 'occupied square footage', 'lease expiration dates'], ['4 overlook point and other locations lincolnshire illinois', '1279000', '2014 - 2019'], ['2601 research forest drive the woodlands texas', '414000', '2020'], ['2300 discovery drive orlando florida', '364000', '2020'], ['devonshire square and other locations london uk', '339000', '2018 - 2028'], ['199 water street new york new york', '337000', '2018'], ['1000 n . milwaukee avenue glenview illinois', '233000', '2017'], ['7201 hewitt associates drive charlotte north carolina', '218000', '2015']]
7201 hewitt associates drive , charlotte , north carolina ............................218000 2015 the locations in lincolnshire , illinois , the woodlands , texas , orlando , florida , and charlotte north carolina , each of which were acquired as part of the hewitt acquisition , are primarily dedicated to our hr solutions business .the other locations listed above house personnel from each of our business segments. .

Question: from the data given , how many square feet have an expiry date in 2020?
Answer: 778000