abiomed , inc .
2005 annual report : financials page 15 notes to consolidated financial statements 2014 march 31 , 2005 in addition to compensation expense related to stock option grants , the pro forma compensation expense shown in the table above includes compensation expense related to stock issued under the company 2019s employee stock purchase plan of approximately $ 44000 , $ 19000 and $ 28000 for fiscal 2003 , 2004 and 2005 , respectively .
this pro forma compensation expense may not be representative of the amount to be expected in future years as pro forma compensation expense may vary based upon the number of options granted and shares purchased .
the pro forma tax effect of the employee compensation expense has not been considered due to the company 2019s reported net losses .
( t ) translation of foreign currencies the u.s .
dollar is the functional currency for the company 2019s single foreign subsidiary , abiomed b.v .
the financial statements of abiomed b.v .
are remeasured into u.s .
dollars using current rates of exchange for monetary assets and liabilities and historical rates of exchange for nonmonetary assets .
foreign exchange gains and losses are included in the results of operations in other income , net .
( u ) recent accounting pronouncements in november 2004 , the financial accounting standards board ( fasb ) issued sfas no .
151 , inventory costs ( fas 151 ) , which adopts wording from the international accounting standards board 2019s ( iasb ) standard no .
2 , inventories , in an effort to improve the comparability of international financial reporting .
the new standard indicates that abnormal freight , handling costs , and wasted materials ( spoilage ) are required to be treated as current period charges rather than as a portion of inventory cost .
additionally , the standard clarifies that fixed production overhead should be allocated based on the normal capacity of a production facility .
the statement is effective for the company beginning in the first quarter of fiscal year 2007 .
adoption is not expected to have a material impact on the company 2019s results of operations , financial position or cash flows .
in december 2004 , the fasb issued sfas no .
153 , exchanges of nonmonetary assets ( fas 153 ) which eliminates the exception from fair value measurement for nonmonetary exchanges of similar productive assets and replaces it with a general exception from fair value measurement for exchanges of nonmonetary assets that do not have commercial substance .
the company is required to adopt fas 153 for nonmonetary asset exchanges occurring in the second quarter of fiscal year 2006 and its adoption is not expected to have a significant impact on the company 2019s consolidated financial statements .
in december 2004 the fasb issued a revised statement of financial accounting standard ( sfas ) no .
123 , share-based payment ( fas 123 ( r ) ) .
fas 123 ( r ) requires public entities to measure the cost of employee services received in exchange for an award of equity instruments based on the grant-date fair value of the award and recognize the cost over the period during which an employee is required to provide service in exchange for the award .
in april 2005 , the the fair value per share of the options granted during fiscal 2003 , 2004 and 2005 was computed as $ 1.69 , $ 1.53 and $ 3.94 , per share , respectively , and was calculated using the black-scholes option-pricing model with the following assumptions. .

2003
2004
2005
risk-free interest rate
2.92% ( 2.92 % )
2.56% ( 2.56 % )
3.87% ( 3.87 % )
expected dividend yield
2014
2014
2014
expected option term in years
5.0 years
5.3 years
7.5 years
assumed stock price volatility
85% ( 85 % )
86% ( 86 % )
84% ( 84 % )

.

Question: what is the percentage change in the risk-free rate from 2004 to 2005?
Answer: 51.2%
Calculation: subtract(3.87, 2.56), divide(#0, 2.56)