incentive compensation cost the following table shows components of compensation expense , relating to certain of the incentive compensation programs described above : in a0millions a0of a0dollars 2018 2017 2016 charges for estimated awards to retirement-eligible employees $ 669 $ 659 $ 555 amortization of deferred cash awards , deferred cash stock units and performance stock units 202 354 336 immediately vested stock award expense ( 1 ) 75 70 73 amortization of restricted and deferred stock awards ( 2 ) 435 474 509 .
( 1 ) represents expense for immediately vested stock awards that generally were stock payments in lieu of cash compensation . the expense is generally accrued as cash incentive compensation in the year prior to grant . ( 2 ) all periods include amortization expense for all unvested awards to non-retirement-eligible employees. .
In millions of dollars 2018 2017 2016
Charges for estimated awards to retirement-eligible employees $669 $659 $555
Amortization of deferred cash awards, deferred cash stock units and performance stock units 202 354 336
Immediately vested stock award expense<sup>(1)</sup> 75 70 73
Amortization of restricted and deferred stock awards<sup>(2)</sup> 435 474 509
Other variable incentive compensation 640 694 710
Total $2,021 $2,251 $2,183
in millions of dollars 2018 2017 2016
charges for estimated awards to retirement-eligible employees $ 669 $ 659 $ 555
amortization of deferred cash awards deferred cash stock units and performance stock units 202 354 336
immediately vested stock award expense ( 1 ) 75 70 73
amortization of restricted and deferred stock awards ( 2 ) 435 474 509
other variable incentive compensation 640 694 710
total $ 2021 $ 2251 $ 2183
what was the percentage change in the total incentive compensation from 2017 to 2018