SUPPLEMENTAL CASH FLOW INFORMATION
During the year ended December 31, 2013, we paid $250.4 million in interest, net of amounts capitalized, and received $39.6 million in net refunds from income taxes. During the year ended December 31, 2012, we paid $241.2 million in interest, net of amounts capitalized, and received $107.0 million in net refunds from income taxes. During the year ended December 31, 2011, we paid $234.0 million in interest, net of amounts capitalized, and received $109.1 million in net refunds from income taxes.
As of December 31, 2013, 2012 and 2011, the amount of accounts payable related to capital expenditures was $4.7 million, $15.7 million and $16.7 million, respectively.
During the years ended December 31, 2013, 2012 and 2011, total amortization of deferred revenue was $56.5 million, $54.9 million and $54.4 million, respectively.
