Notes to Consolidated Financial Statements [in thousands of Canadian dollars, except per share amounts] December 31, 2012 and 2011 2. CAPITAL ASSETS 60 Capital assets consist of the following: Computer Offi ce Leasehold  hardware equipment improvements  Total  $ $ $ $ Cost  Balance, December 31, 2010  18,872  12,401  48,068  79,341 Additions 4,371 1,880 15,226 21,477 Retired (11,444) (4,888) (9,832) (26,164) Balance, December 31, 2011  11,799  9,393  53,462  74,654 Additions 607 791 4,162 5,560 Retired (751) (6) — (757) Balance, December 31, 2012  11,655  10,178  57,624  79,457 Accumulated depreciation Balance, December 31, 2010  15,893  8,816  16,699  41,408 Depreciation 2,805 1,177 5,794 9,776 Retired (11,444) (4,888) (9,832) (26,164) Balance, December 31, 2011  7,254  5,105  12,661  25,020 Depreciation 2,500 1,239 4,576 8,315 Retired (751) (6) — (757) Balance, December 31, 2012  9,003  6,338  17,237  32,578 Carrying amounts At December 31, 2010  2,979  3,585  31,369  37,933 At December 31, 2011  4,545  4,288  40,801  49,634 At December 31, 2012  2,652  3,840  40,387  46,879