Subject + 占 + Amount/Percentage
The verb 占 (zhàn) means "to account for," "to make up," or "to constitute" a portion of something. It is commonly used with percentages or fractions to indicate how much of a whole something represents. For example, genetics may only 占 a small percentage of behavioral differences.
中国人口占世界总人口的百分之十八左右。
Zhōngguó rénkǒu zhàn le shìjiè zǒng rénkǒu de bǎifēnzhī shíbā zuǒyòu.
China's population accounts for about eighteen percent of the world's total population.
房租占了我每月收入的三分之一。
Fángzū zhàn le wǒ měi yuè shōurù de sān fēn zhī yī.
Rent takes up one-third of my monthly income.
女性员工占公司总人数的百分之六十。
Nǚxìng yuángōng zhàn gōngsī zǒng rénshù de bǎifēnzhī liùshí.
Female employees make up sixty percent of the company's total staff.