1 {

     2     "size": 0,

     3     "query": { "match_all": [] },

     4     "aggs": {

     5         "datestats": {

     6             "nested": {

     7                 "path": "creation_years"

     8             },

     9             "aggs": {

    10                 "years": {

    11                     "terms": {

    12                         "field": "creation_years.year",

    13                         "size": 0,

    14                         "order": {

    15                             "_term": "asc"

    16                         }

    17                     },

    18                     "aggs": {

    19                         "year_count": {

    20                             "sum": {

    21                                 "field": "creation_years.weight"

    22                             }

    23                         }

    24                     }

    25                 }

    26             }

    27         }

    28     }

    29 }