32  Annual Report 9   Property, plant and equipment Movements for each class of property, plant and equipment are Computer equipment f  urniture and fittings o  ffice equipment Leased office equipment Library collection Total $ $ $ $ $ $ Cost or valuation Balance at 1 July 2007 280,693 493,897 55,237 46,561 567,000 1,443,388 Additions 33,495 79,094 10,167 0 89,622 212,378 Disposals 0 0 (250) (46,561) 0 (46,811) Balance at 30 June 2008 314,188 572,991 65,154 0 656,622 1,608,955 Additions 4,006 2,892 489 0 86,451 93,838 Disposal (189,494) 0 0 0 0 (189,494) Balance at 30 June 2009 128,700 575,883 65,643 0 743,073 1,513,299 a  ccumulated depreciation Balance at 1 July 2007 228,246 9,770 6,543 42,687 0 287,246 Depreciation expense 42,317 55,982 12,304 0 124,272 234,875 Eliminate on disposal 0 0 (166) (42,687) 0 (42,853) Balance at 30 June 2008 270,563 65,752 18,681 0 124,272 479,268 Depreciation expense 25,119 58,231 11,737 0 141,273 236,360 Retirement (189,494) 0 0 0 0 (189,494) Balance at 30 June 2009 106,188 123,983 30,418 0 265,545 526,134 Carrying amounts At 1 July 2007 52,447 484,127 48,694 3,874 567,000 1,156,142 At 30 June and   1 July 2008 43,625 507,239 46,473 0 532,350 1,129,687 At 30 June 2009 22,512 451,900 35,225 0 477,528 987,165