How to send 75 percentile of one field(duration) value to kafka servers

Elastic Stack Logstash
1

Hi,
I am trying to send 75 percentile of "duration" field(type is number) value to kafka servers by using logstash pipeline. But i did not get idea how to write aggregate filter in logstash. Could you please help me how to write pipeline. Here i am sharing logstash config which i have now.
input {
elasticsearch {
hosts => ["XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXx"]
index => "abc*"
query => '{"query": {
"bool": {
"must": ,
"filter": [

  {
      "exists": {
        "field": "duration"
      }
    },
{"range": {
  "@timestamp": {
    "gte": "now-1d/d","lt": "now/d"
  }
}}]}} }'

}
}

filter {

aggregate {
task_id => "%{duration}"
code => "
"
push_map_as_event_on_timeout => true
timeout_task_id_field => "duration"
timeout => 60
}
}