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:
| millions                 | 2016    | 2015    | 2014    |
|:-------------------------|:--------|:--------|:--------|
| agricultural products    | $ 3625  | $ 3581  | $ 3777  |
| automotive               | 2000    | 2154    | 2103    |
| chemicals                | 3474    | 3543    | 3664    |
| coal                     | 2440    | 3237    | 4127    |
| industrial products      | 3348    | 3808    | 4400    |
| intermodal               | 3714    | 4074    | 4489    |
| total freight revenues   | $ 18601 | $ 20397 | $ 22560 |
| other revenues           | 1340    | 1416    | 1428    |
| total operating revenues | $ 19941 | $ 21813 | $ 23988 |

Question:
what is the mathematical range for chemical revenue from 2014-2016 , in millions?


pre_text: notes to the consolidated financial statements union pacific corporation and subsidiary companies for purposes of this report , unless the context otherwise requires , all references herein to the 201ccorporation 201d , 201ccompany 201d , 201cupc 201d , 201cwe 201d , 201cus 201d , and 201cour 201d mean union pacific corporation and its subsidiaries , including union pacific railroad company , which will be separately referred to herein as 201cuprr 201d or the 201crailroad 201d .
1 .
nature of operations operations and segmentation 2013 we are a class i railroad operating in the u.s .
our network includes 32070 route miles , linking pacific coast and gulf coast ports with the midwest and eastern u.s .
gateways and providing several corridors to key mexican gateways .
we own 26053 miles and operate on the remainder pursuant to trackage rights or leases .
we serve the western two-thirds of the country and maintain coordinated schedules with other rail carriers for the handling of freight to and from the atlantic coast , the pacific coast , the southeast , the southwest , canada , and mexico .
export and import traffic is moved through gulf coast and pacific coast ports and across the mexican and canadian borders .
the railroad , along with its subsidiaries and rail affiliates , is our one reportable operating segment .
although we provide and analyze revenue by commodity group , we treat the financial results of the railroad as one segment due to the integrated nature of our rail network .
the following table provides freight revenue by commodity group: .
post_text: although our revenues are principally derived from customers domiciled in the u.s. , the ultimate points of origination or destination for some products we transport are outside the u.s .
each of our commodity groups includes revenue from shipments to and from mexico .
included in the above table are freight revenues from our mexico business which amounted to $ 2.2 billion in 2016 , $ 2.2 billion in 2015 , and $ 2.3 billion in 2014 .
basis of presentation 2013 the consolidated financial statements are presented in accordance with accounting principles generally accepted in the u.s .
( gaap ) as codified in the financial accounting standards board ( fasb ) accounting standards codification ( asc ) .
2 .
significant accounting policies principles of consolidation 2013 the consolidated financial statements include the accounts of union pacific corporation and all of its subsidiaries .
investments in affiliated companies ( 20% ( 20 % ) to 50% ( 50 % ) owned ) are accounted for using the equity method of accounting .
all intercompany transactions are eliminated .
we currently have no less than majority-owned investments that require consolidation under variable interest entity requirements .
cash and cash equivalents 2013 cash equivalents consist of investments with original maturities of three months or less .
accounts receivable 2013 accounts receivable includes receivables reduced by an allowance for doubtful accounts .
the allowance is based upon historical losses , credit worthiness of customers , and current economic conditions .
receivables not expected to be collected in one year and the associated allowances are classified as other assets in our consolidated statements of financial position. .
label: 190
qa: answer: 190
ann_table_rows: 3
ann_text_rows: 10
steps: op: minus2-1
arg1: 3664
arg2: 3474
res: 190
program: subtract(3664, 3474)
gold_inds: table_3: millions the chemicals of 2016 is 3474 ; the chemicals of 2015 is 3543 ; the chemicals of 2014 is 3664 ;
text_10: the following table provides freight revenue by commodity group: .
exe_ans: 190
tfidftopn: table_8: millions The other revenues of 2016 is 1340 ; The other revenues of 2015 is 1416 ; The other revenues of 2014 is 1428 ;
program_re: subtract(3664, 3474)
model_input: text_1
1 .
text_10
the following table provides freight revenue by commodity group: .
table_3
millions the chemicals of 2016 is 3474 ; the chemicals of 2015 is 3543 ; the chemicals of 2014 is 3664 ;