In the context of this series of interconnected finance-related queries and the additional information provided by the pretext, table data, and posttext from a company's financial filings, please provide a response to the final question. This may require extracting information from the context and performing mathematical calculations. Please take into account the information provided in the preceding questions and their answers when formulating your response:
Context: 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 . <table class='wikitable'><tr><td>1</td><td>in millions of dollars</td><td>2018</td><td>2017</td><td>2016</td></tr><tr><td>2</td><td>charges for estimated awards to retirement-eligible employees</td><td>$ 669</td><td>$ 659</td><td>$ 555</td></tr><tr><td>3</td><td>amortization of deferred cash awards deferred cash stock units and performance stock units</td><td>202</td><td>354</td><td>336</td></tr><tr><td>4</td><td>immediately vested stock award expense ( 1 )</td><td>75</td><td>70</td><td>73</td></tr><tr><td>5</td><td>amortization of restricted and deferred stock awards ( 2 )</td><td>435</td><td>474</td><td>509</td></tr><tr><td>6</td><td>other variable incentive compensation</td><td>640</td><td>694</td><td>710</td></tr><tr><td>7</td><td>total</td><td>$ 2021</td><td>$ 2251</td><td>$ 2183</td></tr></table> ( 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. .
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Question: what is the difference in total incentive compensation from 2017 to 2018?
Answer: