The aged in Japan now make up about 11% of the population, but this figure will rise to 25% by the year2025, seven percentage points higher than in the U.S.
スラッシュは主語、述語の後、カンマの後、前置詞の
前に入れます。
The aged in Japan /now make up /about 11% of the population,/ but this figure will rise /to 25%/ by the year 2025,/ seven percentage points higher/ than in the U.S.