How to show sub total and grand total?

Hello, Deo,
 
Thank you for providing a sample data set and giving us some time.
 
We would like to explain that at the moment the desired output can be achieved by displaying the three sections (the data table, airline totals, and sales totals) separately. Each section can be displayed in Flexmonster by applying a different data slice.
 
Please see the following JSFiddle example we have prepared for you: https://jsfiddle.net/flexmonster/ejb8t7kp/
 
We would like to add that to achieve the closest to the provided screenshot result, we have made a few changes to the data structure:
Instead of:

{
  "AIRLINE": "sample airline",
  "STATE": "ACT",
  "Year": "2017",
  "DATA": "Passengers 2017",
  "JAN": 0,
  "FEB": 0,
  "MAR": 0,
  "JUL": 0,
  "AUG": 0,
  "SEP": 0,
  "OCT": 0,
  "NOV": 0,
  "DEC": 0,
  "Grand Total": 0
}

We kindly suggest the following:

 {
   "AIRLINE": "sample airline",
   "STATE": "ACT",
   "Year": "2017",
   "Month": "JAN",
   "Passengers": 0,
   "Sales (Fares Only)": 0
}

 
Please let us know if this helps.
You are welcome to write to us in case any additional questions arise.
 
Kind regards,
Vera