N of n
The 'percentage' group
The noun indicates a portion of a larger thing or group. The noun group after of indicates the thing or group concerned.
Opinion polls showed the majority of people were opposed to the agreement.
The percentage of girls in engineering has increased substantially in the past few years.
A portion of the royalties will be donated to the Salvation Army.
In the case of ratio and proportion the noun group after of is often followed by a prepositional phrase introduced by to.
bit bulk concentration majority minority percentage portion proportion ratio
The ratio of public spending to national income has fallen by more than 7 percentage points.