Simplify the following text for a Grade 9 native English-speaking person.
Original: Jupiter 's upper atmosphere is composed of about 88 â `` 92 % hydrogen and 8 â `` 12 % helium by percent volume or fraction of gas molecules ( see table to the right ) .
Simplified: The atmosphere near the surface of Jupiter is made of about 88 to 92 % hydrogen , 8 to 12 % helium , and 1 % other gases .