Prospectus excerpt:  We are offering to the public 8,000,000 shares of our 6.375% Series D Cumulative Redeemable Preferred Stock, par value $0.01 per share, which we refer to in this prospectus supplement as the Series D Preferred Stock. This is the initial issuance of the Series D Preferred Stock. We will pay quarterly cumulative cash dividends on the Series D Preferred Stock, in arrears, on the 30th day of January, April, July and October of each year (provided that if any dividend payment date is not a business day, then the dividend which would otherwise have been payable on that dividend payment date may be paid on the next succeeding business day) from and including the date of original issuance at 6.375% of the $25.00 per share liquidation preference per annum (equivalent to $1.59375? per annum per share). Dividends will be payable, when, as and if authorized by our board of directors and declared by us, to holders of record as they appear in our stock records for the Series D Preferred Stock at the close of business on the applicable record date, which shall be the fifteenth day of the calendar month, whether or not a business day, in which the applicable dividend payment date falls. The first dividend on the Series D Preferred Stock sold in this offering will be payable on July 30, 2021 and will be in the amount of $0.25677 per share.