The income statement in exhibit $1\mathrm{.}27$ shows depreciation and amortization expense as:

$2012-$ $$550\mathrm{.}3$ million

$2011-$ $$523\mathrm{.}3$ million

$2010-$ $$510\mathrm{.}4$ million

However yhe statement of cash flows shows addbacks for depreciation and amoritization as follows:

$2012-$ $$580\mathrm{.}6$ million

$2011-$ $$550$ million

$2010-$ $$540\mathrm{.}8$ million

why is the amount on the income statement different from the amount on the statement of cash flows each year?