How do create range bar graph directly in C# (using System.Windows.Forms.DataVisualization.Charting.Chart) . by manual key-in datapoints

See more:

C#

Create range bar graph directly in C# (using System.Windows.Forms.DataVisualization.Charting.Chart) . by manual key-in datapoints, try to generate a similar output as below (in paper and in C#). Add the following data also:
1. data point(blue) with X value = 3, Y value = 5,12, X value = 4, Y value 8,21,
2. data point(green) with X value = 3, Y value = +4 at the end of the blue data point with value X =3; X value = 4, Y value = +6 at the end of the blue data point with X value = 4

green data points should always touch the end of blue data points at the right most but cannot overlap on any blue data points