How to retrieve array of array values from json

{
   "status":"Success",
   "message":"Data Found...!",
   "data":[
      {
         "Order_Count":"14",
         "Ward_Count":"14",
         "GrandTotal_Amount":"9095",
         "Tax_Amount":"268.84",
         "item":[
            {
               "ItemName":"GRILLED CHICKEN FULL",
               "TotalQuantity":"1",
               "TotalAmount":"470"
            },
            {
               "ItemName":"RAVA UPMA",
               "TotalQuantity":"1",
               "TotalAmount":"75.0"
            }
         ]
      }
   ]
}

i am able to retreive "Order_Count" value and get a result by using this..

let orders = json["data"].arrayValue.map{$0["Order_Count"].stringValue}

how to retreive "ItemName" value from this array