Simplify the following text for a Grade 10 native English-speaking person.
Original: At a Reference Group meeting in Belgrade it was decided that the existing rules will remain in place , and that the number of participants in the final will simply be lowered from twenty-five to twenty-four .
Simplified: And it was decided that the existing rules will remain in place , and that the number of participants in the final will simply decreased from twenty-five to twenty-four .