Task: Table-QA (source dataset: FinQA)

Task: 
You are given a table containing structured data and a natural language question referring to the table. Your goal is to analyze the table and provide an accurate and concise answer based on the given data.

Instructions:
1. Understand the Table: Examine the structure, headers, and data in the table. Identify relevant columns and rows related to the question.
2. Interpret the Question: Determine whether the question requires direct retrieval, aggregation, comparison, sorting, filtering, or inference.
3. Extract the Answer: Use logical reasoning and numerical operations (if necessary) to derive the correct response from the table.
4. Format the Answer: No explanation, return the answer in a structured JSON format: {"answer": <answer>}. If the question cannot be answered due to missing or ambiguous data, return a JSON response with {"answer": null}.

Table:
| Unnamed: 0                     | 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?


pre_text: 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. .
post_text: .
label: 0.5117200000000001
qa: answer: 51.2%
ann_table_rows: 1
steps: op: minus2-1
arg1: 3.87
arg2: 2.56
res: 1.31
op: divide2-2
arg1: #0
arg2: 2.56
res: 51.2%
program: subtract(3.87, 2.56), divide(#0, 2.56)
gold_inds: table_1: the risk-free interest rate of 2003 is 2.92% ( 2.92 % ) ; the risk-free interest rate of 2004 is 2.56% ( 2.56 % ) ; the risk-free interest rate of 2005 is 3.87% ( 3.87 % ) ;
exe_ans: 0.5117200000000001
tfidftopn: text_23: 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. .
text_1: 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 .
program_re: divide(subtract(3.87, 2.56), 2.56)
model_input: text_1
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 .
text_23
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. .
table_1
the risk-free interest rate of 2003 is 2.92% ( 2.92 % ) ; the risk-free interest rate of 2004 is 2.56% ( 2.56 % ) ; the risk-free interest rate of 2005 is 3.87% ( 3.87 % ) ;