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                | shares       | weighted averagegrant-datefair value   |
|:--------------------------|:-------------|:---------------------------------------|
| non-vested at may 31 2011 | 869          | $ 40                                   |
| granted                   | 472          | 48                                     |
| vested                    | -321 ( 321 ) | 40                                     |
| forfeited                 | -79 ( 79 )   | 43                                     |
| non-vested at may 31 2012 | 941          | 44                                     |
| granted                   | 561          | 44                                     |
| vested                    | -315 ( 315 ) | 43                                     |
| forfeited                 | -91 ( 91 )   | 44                                     |
| non-vested at may 31 2013 | 1096         | $ 44                                   |

Question:
what was the average unrecognized compensation cost related to unvested restricted stock per year?


pre_text: grants of restricted awards are subject to forfeiture if a grantee , among other conditions , leaves our employment prior to expiration of the restricted period .
new grants of restricted awards generally vest one year after the date of grant in 25% ( 25 % ) increments over a four year period , with the exception of tsrs which vest after a three year period .
the following table summarizes the changes in non-vested restricted stock awards for the years ended may 31 , 2013 and 2012 ( share awards in thousands ) : shares weighted average grant-date fair value .
post_text: the total fair value of share awards vested during the years ended may 31 , 2013 , 2012 and 2011 was $ 13.6 million , $ 12.9 million and $ 10.8 million , respectively .
we recognized compensation expense for restricted stock of $ 16.2 million , $ 13.6 million , and $ 12.5 million in the years ended may 31 , 2013 , 2012 and 2011 , respectively .
as of may 31 , 2013 , there was $ 33.5 million of total unrecognized compensation cost related to unvested restricted stock awards that is expected to be recognized over a weighted average period of 2.5 years .
employee stock purchase plan we have an employee stock purchase plan under which the sale of 2.4 million shares of our common stock has been authorized .
employees may designate up to the lesser of $ 25000 or 20% ( 20 % ) of their annual compensation for the purchase of stock .
the price for shares purchased under the plan is 85% ( 85 % ) of the market value on the last day of the quarterly purchase period .
as of may 31 , 2013 , 1.0 million shares had been issued under this plan , with 1.4 million shares reserved for future issuance .
we recognized compensation expense for the plan of $ 0.5 million in the years ended may 31 , 2013 , 2012 and 2011 .
the weighted average grant-date fair value of each designated share purchased under this plan during the years ended may 31 , 2013 , 2012 and 2011 was $ 6 , $ 7 and $ 6 , respectively , which represents the fair value of the 15% ( 15 % ) discount .
stock options stock options are granted at 100% ( 100 % ) of fair market value on the date of grant and have 10-year terms .
stock options granted vest one year after the date of grant in 25% ( 25 % ) increments over a four year period .
the plans provide for accelerated vesting under certain conditions .
there were no options granted under the plans during the years ended may 31 , 2013 and may 31 , 2012. .
label: 13.4
qa: answer: $ 13.4 million
explanation: in line 6 , it states that the total unrecognized compensation cost related to unvested restricted stock was 33.5 million over a 2.5 year span . therefore it would be 13.4 million per year .
ann_text_rows: 5
steps: op: divide2-1
arg1: 33.5
arg2: 2.5
res: 13.4
program: divide(33.5, 2.5)
gold_inds: text_5: as of may 31 , 2013 , there was $ 33.5 million of total unrecognized compensation cost related to unvested restricted stock awards that is expected to be recognized over a weighted average period of 2.5 years .
exe_ans: 13.4
tfidftopn: text_1: new grants of restricted awards generally vest one year after the date of grant in 25% ( 25 % ) increments over a four year period , with the exception of tsrs which vest after a three year period .
text_13: stock options granted vest one year after the date of grant in 25% ( 25 % ) increments over a four year period .
program_re: divide(33.5, 2.5)
model_input: text_2
the following table summarizes the changes in non-vested restricted stock awards for the years ended may 31 , 2013 and 2012 ( share awards in thousands ) : shares weighted average grant-date fair value .
text_4
we recognized compensation expense for restricted stock of $ 16.2 million , $ 13.6 million , and $ 12.5 million in the years ended may 31 , 2013 , 2012 and 2011 , respectively .
text_5
as of may 31 , 2013 , there was $ 33.5 million of total unrecognized compensation cost related to unvested restricted stock awards that is expected to be recognized over a weighted average period of 2.5 years .