How to create custom aggregation of Measure ?

I want to create aggregation of Sum(PMO) vs Sum (AOP)
but always return Zero or Infinity,
 
How to solve this ?

,
"measures": [
     {
       "uniqueName": "AOP",
       "aggregation": "sum"
     },
     {
       "uniqueName": "PMO",
       "aggregation": "sum"
     },
     {
       "uniqueName": "STD",
       "aggregation": "sum"
     },
     {
       "uniqueName": "STT",
       "aggregation": "sum"
     },
     {
       "uniqueName": "PMO vs AOP",
       "formula": "sum(\"PMO\") / sum(\"AOP\") * 100",
       "individual": true,
       "caption": "PMO/AOP"
     }
],

Thanks