How to set the widths of labels dynamically inside a list View Row based on Device Screen Size

I have a List View with header and multiple rows. I can able to fix the Headers based on Screen Size. But I unable to fix the Data based on Screen Size.

Here is my code.

Row LayOut:

public class CICell : ViewCell
{
public CICell()
{

        var numberLabel = new Label{ 
            WidthRequest = 30, // I need these should be dynamic
        };
        numberLabel.SetBinding (Label.TextProperty, "No");

        var brandNameLabel = new Label{ 
            WidthRequest = 50, // I need these should be dynamic
        };
        brandNameLabel.SetBinding (Label.TextProperty, "BrandName");

        var productCategoryLabel = new Label{ 
            WidthRequest = 150, // I need these should be dynamic
        };
        productCategoryLabel.SetBinding (Label.TextProperty, "ProductCategory");

        var productRangeLabel = new Label{ 
            WidthRequest = 150, // I need these should be dynamic
        };
        //productRangeLabel.SetBinding (Label.WidthProperty, "2*");
        productRangeLabel.SetBinding (Label.TextProperty, "ProductRange");

        var packingInnovationLabel = new Label{ 
            WidthRequest = 150, // I need these should be dynamic
        };
        packingInnovationLabel.SetBinding (Label.TextProperty, "PackingInnovation");

        var pricingLabel = new Label { 
            WidthRequest = 100,
        };
        pricingLabel.SetBinding (Label.TextProperty, "Pricing");

        var stateLabel = new Label{ 
            WidthRequest = 50,
        };
        stateLabel.SetBinding (Label.TextProperty, "State");

        var rowLayout = new StackLayout { 
            Orientation = StackOrientation.Horizontal,
            Children = {
                numberLabel,
                brandNameLabel,
                productCategoryLabel,
                productRangeLabel,
                packingInnovationLabel,
                pricingLabel,
                stateLabel
            },
        };

        View = rowLayout;
    }

}

public class CompetitiveIntelligencePage : ContentPage
{
public double width { get; set; }
public CompetitiveIntelligencePage ()
{
SizeChanged += (object sender, EventArgs e) => {
width = Width;
var listView = new ListView{
RowHeight = 40,
};

            listView.ItemTemplate = new DataTemplate (typeof(CICell));   

            listView.ItemsSource = CompetitiveIntelligenceList;
            var tableHeaderLayout = new StackLayout {
                Orientation = StackOrientation.Horizontal,
                HeightRequest = 100,
                Children = {
                    new Label{Text = "No",WidthRequest = (0.5*width)/10 },
                    new Label{Text = "Brand Name", WidthRequest = (1.1*width)/10},
                    new Label {Text = "Prodcut Category", WidthRequest = (1.9*width)/10},
                    new Label {Text = "Product Range", WidthRequest = (2*width)/10},
                    new Label{Text = "Packing Innovation", WidthRequest = (1.5*width)/10},
                    new Label{Text = "Pricing: Sell Out (Per Price)", WidthRequest = (1.5*width)/10},
                    new Label{Text = "State (Drop Down Option)",WidthRequest = (1.5*width)/10}
                }
            };

            Content = new StackLayout { 
                Orientation = StackOrientation.Vertical,
                VerticalOptions = LayoutOptions.FillAndExpand,
                Children = {headerLayout, tableHeaderLayout, listView }
            };
        };

}
}