Question about power supply K7203

Hello, i’ve buy this kit and want to built a flexible power supply which can adjust the voltage from 3 to 30 VDC. But on page 9 are values listed for desired output voltage regarding the input voltage. If i use a transformator with an outputvoltage from 24V - the table show a desired output from 18…22V. What does it mean? Is the range really so small? I expect an output from 3 to 24V - or minimum 22V. Can anybody confirm the correct outputvoltage if i use a 24 V Trafo?