         activeUserCount = 0
         maxActiveUserCount = 0
         activeUserHistory.removeAll()
-        let originDate = Date().addingTimeInterval(chartDuration * -1)
-        for i in 0...Int(chartDuration / calculateActiveUserInterval) {
-            let date = originDate.addingTimeInterval(calculateActiveUserInterval * Double(i))
-            activeUserHistory.append((date, 0))
-        }
-        // updateActiveUserLabels()
-        // updateActiveUserChart()
+        updateActiveUserLabels()
+        updateActiveUserChart()
     }
 
     func updateActiveUserLabels() {
+        if activeUserHistory.isEmpty {
+            activeUserValueLabel.stringValue = defaultLabelValue
+            maxActiveUserValueLabel.stringValue = defaultLabelValue
+            return
+        }
         activeUserValueLabel.stringValue = String(activeUserCount)
         maxActiveUserValueLabel.stringValue = String(maxActiveUserCount)
     }

    func updateActiveUser(active: Int) {
        activeUserCount = active
        maxActiveUserCount = max(maxActiveUserCount, active)
        activeUserHistory.append((Date(), active))
        activeUserHistory = activeUserHistory.filter { Date().timeIntervalSince($0.0) < chartDuration }
    }

        ds.drawCirclesEnabled = false
        ds.drawValuesEnabled = false
        ds.highlightEnabled = false
        data.append(ds)
        if 0 < maxActiveUserCount {
            activeUserChartView.leftAxis.axisMaximum = Double(maxActiveUserCount) * 1.05
        }
        activeUserChartView.data = data
    }
}

