The amount of cash and securities held by Apple at the end of each fiscal year, which runs through late September:
2005: $8.3 billion.
2006: $10.1 billion.
2007: $15.4 billion.
2008: $24.5 billion.
2009: $34 billion.
2010: $51 billion.
2011: $81.6 billion.
Source: Apple annual reports