Simplify the following text for a Grade 7 native English-speaking person.
Original: Of those , an estimated 80 â `` 90 % are Sunni and 10 â `` 20 % are Shi ` a , with a small minority belonging to other sects .
Simplified: Of those , between 75 % and 90 % are Sunni and between ten and twenty percent are Shi ` a . A small minority belong to other Islamic sects .