shipments of computing devices : PC vs Notebooks vs Tablets

The chart maps the growth of computing devices , between  Desktops , PCs, Notebooks, and tablets

The growth of tablets have been astonishing, from zero to almost 80million in 3 years. Meanwhile  the number of Desktops shipped every quarter  has been growing till  2009 , from where it started declining ( Apple, Ipad and Samsung's  Tablets were just about to hit the market .Notebooks  have seen a jump recently as in the 2009 Q1 , around 50million notebooks were shipped  which again started declining .