Percentage
Ratio
noun
You compare the percent and by doing that figure out the percentage and ratio of something.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
うちの会社の男女比率は、5:2です。
The male to female ratio in our company is 5:2.
それってGDP比率の何パーセントぐらいですか？
Approximately what percentage of GDP is that?
何かを学ぼうとするときは、インプットとアウトプットの比率を考えながら学ぶといいですよ。
When you are trying to learn something, you should consider the ratio of input to output.