Prospectus excerpt:  We are offering and selling 6,000,000 of our depositary shares, each of which represents 1/1000 of a 5.000% Series C Cumulative Redeemable Preferred Share of Beneficial Interest that we have deposited with The American Stock Transfer & Trust Company, LLC as depositary. We will receive the net proceeds from the sale of the depositary shares. As a holder of a depositary share, you will be entitled to proportional rights and preferences as if you held 1/1000 of a Series C preferred share. Dividends on the Series C preferred shares represented by the depositary shares will be cumulative from, and including, the date of original issue and will be payable, subject to authorization by our board of trustees and declaration by us, quarterly in arrears on January 15, April 15, July 15 and October 15 of each year (or, if such date is not a business day, on the next succeeding business day), commencing on January 15, 2018, at the rate of 5.000% of the $25,000.00 liquidation preference per year, or $1,250.00 per year, per Series C preferred share (equal to $1.250 per year per depositary share).