Need Idea foreach

where your getting data from?
if this data in database you can use group by and sum sql functions to get

viewed | code
25        | US
85        | SG
55         | MY

or if discribe it in php array: 

PHP Code:

array(
  array('viewed' => 25, 'code' => 'US'),
  array('viewed' => 85, 'code' => 'SG'),
  array('viewed' => 55, 'code' => 'MY')
) 


your gdpData is in json format. you will need to map to 

PHP Code:

array(
    'US' => 25,
    'SG' => 85,
    'MY' => 55
) 


 this format and then use json_encode PHP function. it will give following result:

{"US":25,"SG":85,"MY":55}

Also to parse json you can use json_decode function in PHP