You set the level of your YEL income

As an entrepreneur you determine the appropriate level of your YEL income. YEL income equal the value of your work input. It should equal the sum that would be paid to an employee with the same professional skills as you have.

The YEL contribution is calculated on the basis of the YEL income you have reported to us. You may change your YEL income as your self-employed activities or your work input changes, but you cannot do this retroactively.