Introduced an new label to set the scaling factor that is used to calculate th proportions, setting it to 0 also allows to disable scaling.
Updated the tests to reflect the changes and added a new test which shows that setting the scaling factor to 0 indeed does disable scaling.
Ensured that the scaling factor is always between [0 and 100].
Signed-off-by: Simon Pelczer <templum.dev@gmail.com>