An example of an order for physical therapy with a ratio quantity

{
  "resourceType" : "ServiceRequest",
  "id" : "physicaltherapy",
  "identifier" : [{
    "value" : "12345"
  }],
  "status" : "completed",
  "intent" : "order",
  "code" : {
    "concept" : {
      "coding" : [{
        "system" : "http://snomed.info/sct",
        "code" : "722138006",
        "display" : "Physical therapy"
      }],
      "text" : "Physical therapy"
    }
  },
  "quantityRatio" : {
    "numerator" : {
      "value" : 20,
      "unit" : "treatment"
    },
    "denominator" : {
      "value" : 1,
      "unit" : "month"
    }
  },
  "subject" : {
    "reference" : "Patient/example"
  },
  "authoredOn" : "2017-03-05",
  "requester" : {
    "reference" : "Practitioner/3ad0687e-f477-468c-afd5-fcc2bf897809",
    "display" : "Dr. Beverly Crusher"
  }
}