Elastic search function score query

[Ali_Ahmed]

I want result which is based on 3 things CreationDate 65% , cars 20%, motorbike 15%

Data which is inserted in elasticsearch

{
"created": "2018-03-20T14:19:15Z",
"username": "adamcharles",
"stats": {
  "cars": 20,
  "motorbike ": 30
  }
},
{
"created": "2017-03-20T14:19:15Z",
"username": "adamcharles",
"stats": {
  "cars ": 100,
  "motorbike ": 20
  }
}

query of elastic search

GET showroom/_search

 "query": { 
        "function_score":{
          "functions": [
            { 
              "gauss": {
                "created": {
                  "origin": "now",
                  "scale": "10d", 
                  "decay" :0.9
               }
             }
           }
           ,{ 
              "field_value_factor": {
                "field": "stats.motorbike",
                "factor": 15,
                "modifier": "sqrt",
                "missing": 1
              }
            },
            {
              "field_value_factor": {
                "field": "stats.cars",
                "factor": 20,
                "modifier": "sqrt",
                "missing": 1
              }
            }          ], 
          "score_mode": "sum",
          "boost_mode": "sum"
        }
    }

how can i apply factor on created date