iOS Charts -> Last value doesn't appear

Question

I have some troubles with the library, when I create a barChart I have to add an extra value to my values array in order to show all my original values, and in the lineChart the last value appears in the line graph but it doesn't have its value above the point like the others.

I let you my code and some pictures showing the problem:

BarChart: My xAxis have a custom format showing months.

override func viewDidLoad() {
    super.viewDidLoad()

    let unitsSold = [20.0, 4.0, 6.0, 3.0, 12.0, 16.0, 4.0, 18.0, 2.0, 4.0, 5.0, 4.0]
    max = unitsSold.maxElement()        

    setChart(unitsSold)        
}


func setChart(values: [Double]) {

    let formato:BarChartFormatter = BarChartFormatter()
    let xaxis:XAxis = XAxis()

    barChartView.noDataText = "You need to provide data for the chart."

    var dataEntries: [BarChartDataEntry] = []

    for i in 0..<values.count {
        let dataEntry = BarChartDataEntry(x: Double(i), y:values[i])
        dataEntries.append(dataEntry)

        formato.stringForValue(Double(i), axis: xaxis)
    }

    xaxis.valueFormatter = formato

    let chartDataSet = BarChartDataSet(values: dataEntries, label: "Units Sold")
    chartDataSet.colors = ChartColorTemplates.joyful()

    barChartView.fitBars = true //Para que las barras inicial y final se muestren completas
    barChartView.xAxis.valueFormatter = xaxis.valueFormatter
    barChartView.xAxis.labelPosition = .Bottom
    barChartView.leftAxis.axisMinimum = 0
    barChartView.leftAxis.axisMaximum = max + 2
    barChartView.rightAxis.enabled = false
    barChartView.drawValueAboveBarEnabled = false
    barChartView.descriptionText = ""
    barChartView.xAxis.drawGridLinesEnabled = false
    barChartView.animate(xAxisDuration: 1.0, yAxisDuration: 1.0)

    let chartData = BarChartData()
    chartData.addDataSet(chartDataSet)
    barChartView.data = chartData
}

LineChart: My xAxis have a custom format showing months.

override func viewDidLoad() {
    super.viewDidLoad()

    let unitsSold = [20.0, 4.0, 6.0, 3.0, 12.0, 16.0]
    max = unitsSold.maxElement()

    setChart(unitsSold)   
}

func setChart(values: [Double]) {

    let formato:BarChartFormatter = BarChartFormatter()
    let xaxis:XAxis = XAxis()

    var dataEntries: [ChartDataEntry] = []

    for i in 0..<values.count {
        let dataEntry = ChartDataEntry(x: Double(i), y: values[i])
        dataEntries.append(dataEntry)

        formato.stringForValue(Double(i), axis: xaxis)
    }

    xaxis.valueFormatter = formato

    let lineChartDataSet = LineChartDataSet(values: dataEntries, label: "Units Sold")
    lineChartDataSet.colors = ChartColorTemplates.joyful()
    lineChartDataSet.circleColors = ChartColorTemplates.joyful()
    lineChartDataSet.drawCircleHoleEnabled = false


    let lineChartData = LineChartData( dataSet: lineChartDataSet)
    lineChartData.setValueFont(UIFont(name: "HelveticaNeue-Light", size: 7))

    lineChartView.fitScreen()
    lineChartView.xAxis.labelPosition = .Bottom
    lineChartView.xAxis.axisMaximum = Double(values.count) 
    lineChartView.leftAxis.axisMinimum = 0
    lineChartView.leftAxis.axisMaximum = max + 3
    lineChartView.rightAxis.enabled = false
    lineChartView.descriptionText = ""
    lineChartView.xAxis.drawGridLinesEnabled = false
    lineChartView.animate(xAxisDuration: 1.0, yAxisDuration: 1.0)
    lineChartView.xAxis.valueFormatter = xaxis.valueFormatter

    lineChartView.data = lineChartData
 }

The responses are: For barChart December doesn't appear and in lineChart the last value doesn't show its value above it, I hope someone can help.