     var birthDate: Date
     var heightInMeters: Float
     private var sexInBoolean: Bool
-    var bloodPressureMeasurements: [BloodPressureMeasurement]
+    private var bloodPressureMeasurementsSorted: [BloodPressureMeasurement]
+    public var bloodPressureMeasurements: [BloodPressureMeasurement] {
+        get {
+            return self.bloodPressureMeasurementsSorted
+        }
+        
+        set(newBloodPressureMeasurements) {
+            self.bloodPressureMeasurementsSorted = newBloodPressureMeasurements.sorted {
+                return $0.measurementDate < $1.measurementDate
+            }
+        }
+    }
     
     public var sex: Patient.Sex {
         get {

            case .female: self.sexInBoolean = false
        }
        
        self.bloodPressureMeasurements = bloodPressureMeasurements
    }
    
    // Encoder used to store a patient.

        }
        
        // Blood pressure log is required.
        guard let bloodPressureMeasurementsSorted = decoder.decodeObject(forKey: PropertyKey.bloodPressureMeasurementsSorted) as? [BloodPressureMeasurement] else {
            
            os_log("Unable to decode the blood pressure log for a Patient object.", log: OSLog.default, type: .debug)
            return nil
        }
