のほとんどは

most of

→ の
phrase Rare #28,019
most of Follows a noun or pronoun and means “most of [that group or thing].” は marks the phrase as the topic.
JA: 学生のほとんどは電車で通学します。
EN: Most of the students commute to school by train.

トムお金のほとんどは家族を養うことに回る

Most of Tom's money goes toward supporting his family.

日本一流大学のほとんどは東京にあります

Most of Japan’s top universities are located in Tokyo.

彼らのほとんどは帰宅したと思う

I think most of them went home.

聴衆のほとんどは実業家だった

Most of the audience were businesspeople.

米国の犯罪者のほとんどは麻薬中毒である

Most criminals in the United States are drug addicts.

彼らのほとんどは礼儀正しい

Most of them are polite.