Yap.Town

の数が少ない

there are few

→ の
phrase Rare #41,913
there are few Follows a noun to say that the number of something is small or lower than expected. For a comparison, use より: AよりBの数が少ない means “there are fewer B than A.”
JA: この町は子どもの数が少ない。
EN: There are few children in this town.

母となる女性の数が少ない。

There are few women who become mothers.

彼は僕より友達の数が少ない。

He has fewer friends than I do.