diff --git a/paths/population_statistics.yaml b/paths/population_statistics.yaml
index a5b5553..2f58733 100644
--- a/paths/population_statistics.yaml
+++ b/paths/population_statistics.yaml
@@ -47,41 +47,44 @@ get:
       content:
         application/json:
           schema:
-            type: array
-            items:
-              type: object
-              properties:
-                age:
-                  type: integer
-                  minimum: 0
-                  format: int32
-                  example: 42
-                preferredDoctor:
-                  $ref: '../schemas/PatIdentity.yaml#/doctor'
-                insurer:
+            type: object
+            properties:
+              cohorts:
+                type: array
+                items:
                   type: object
                   properties:
-                    uzovi:
-                      $ref: '../schemas/insurer-Uzovi.yaml'
-                    name:
-                      type: string
-                      description: |-
-                        The name of the insurer according the [Vektis register](https://www.vektis.nl/uzovi-register). If the Uzovi is unknown, the Uzovi code is used as the name. The latest register is used to lookup the name for the code.
-                      example: FBTO Zorgverzekeringen N.V.
-                    concern:
-                      type: string
-                      description: The concern name, if any, otherwise the empty string.
-                      example: ACHMEA
-                    valid:
-                      type: boolean
-                      description: True if the insurer can be validated using the Uzovi table on the reference date.
-                gender:
-                  $ref: '../schemas/PatIdentity.yaml#/gender'
-                n:
-                  type: integer
-                  format: int32
-                  description: "The number of unique patients in the group."
-                  example: 7
+                    age:
+                      type: integer
+                      minimum: 0
+                      format: int32
+                      example: 42
+                    preferredDoctor:
+                      $ref: '../schemas/PatIdentity.yaml#/doctor'
+                    insurer:
+                      type: object
+                      properties:
+                        uzovi:
+                          $ref: '../schemas/insurer-Uzovi.yaml'
+                        name:
+                          type: string
+                          description: |-
+                            The name of the insurer according the [Vektis register](https://www.vektis.nl/uzovi-register). If the Uzovi is unknown, the Uzovi code is used as the name. The latest register is used to lookup the name for the code.
+                          example: FBTO Zorgverzekeringen N.V.
+                        concern:
+                          type: string
+                          description: The concern name, if any, otherwise the empty string.
+                          example: ACHMEA
+                        valid:
+                          type: boolean
+                          description: True if the insurer can be validated using the Uzovi table on the reference date.
+                    gender:
+                      $ref: '../schemas/PatIdentity.yaml#/gender'
+                    n:
+                      type: integer
+                      format: int32
+                      description: "The number of unique patients in the group."
+                      example: 7
     400:
       description: "Common HTTP semantics, see the response body."
     401: