In 2020, total UN system expenditure was US$ 56.2 billion. UN expenditure is usually divided into four activity areas: development assistance, humanitarian assistance, peace operations, and global agenda and specialised assistance. Expenditure on humanitarian assistance and development assistance, collectively referred to as UN operational activities for development (OAD), were roughly equal in 2018. By 2020, humanitarian assistance had grown to 42% of total UN expenditure, while development assistance spending decreased to 30%. OAD accounts for almost three-quarters of total expenditure in the UN system.