Comparisson of gross and net salaries in Germany

I have been checking the site lohnspiegel.de. It has, besides a very complete database of salaries, a tool to calculate the net salary dependent on some variables.
Being single and independent, I am classified as Steuerklasse I, that is, tax category I.
Take a look at the chart below. It shows the monthly net income according to gross yearly salaries. Below the yearly salary you will see the percentage of taxes and other duties in relation to gross salary. Figures in Euro.