Tesseract (tessnet2) cannot read simple numbers

Question

I designed a simple code for extracting the text out of images. The images only contain numbers. This are the images, I want to convert:

The result of the OCR conversion is always ~

For this two images, the OCR conversion is giving results with some mistakes:

Here is my code:

    using Tes = tessnet2;

    private const string TesIni = @"C:\Program Files (x86)\Tesseract\tessdata";

    static void Main(string[] args)
    {
        System.Drawing.Bitmap TextImg = new System.Drawing.Bitmap(@"C:\HomeC\RPA_Prozesse\BOB_NPM_Retour\btnImages\TestTextImage.png");
        Tes.Tesseract ocr = new Tes.Tesseract();
        ocr.Init(TesIni, "eng", true);
        System.Collections.Generic.List<Tes.Word> Result = ocr.DoOCR(TextImg, System.Drawing.Rectangle.Empty);
        foreach(Tes.Word wrd in Result)
        {
            System.Console.WriteLine(wrd.Text);
        }

        System.Console.WriteLine("Application finished. Press any key to exit...");
        System.Console.ReadLine();
    }

In the documentation is written, that "Tesseract" is the best open source OCR-Library and was hardly improved by Google - but the results are extremly poor.

Are there some settings, I can change to get better results?