noun
work force; employed population
Refers to the number of people who are employed, often used in economic or statistical contexts.
この地域の就業人口は年々増加している。
The employed population in this region is increasing year by year.
労働人口 (labor force) includes both employed and unemployed people actively seeking work, while 就業人口 refers specifically to those who are employed.
Compound of 就業 (employment) and 人口 (population).