Leases

The Company is obligated under long-term real estate leases for corporate office space that was extended during the third quarter of 2015. Prior to this extension, the lease would have expired in October 2016, the lease is now set to expire in October 2022 . In addition, the research lab space at CET, under an agreement amended in July 2012, is leased through 2018, with an option to extend the lease through April 2028. The Company also subleases a portion of the space under these leases. Rent expense is recognized over the expected term of the lease, including renewal option periods, if applicable, on a straight-line basis. Rent expense for 2015, 2014 and 2013 was approximately $1.0 million, $1.0 million and $0.9 million, respectively, and sublease income was approximately $0.6 million, $0.5 million and $0.5 million. Cumulative future minimum sublease income under noncancelable operating subleases totals approximately $0.1 million and will be paid through the lease ending in October 2016. Future minimum lease payments under noncancelable operating leases (with initial or remaining lease terms in excess of one year) are as follows:



Year ending December 31:
2016	$	1,075,243
2017	1,039,618
2018	901,568
2019	838,896
2020 and thereafter	2,469,052
Total future minimum lease payments	$	6,324,377