Accordingly, countries have been grouped as high-income, upper-middle-income, lower-middle-income and low-income (table E). To maintain compatibility with similar classifications used elsewhere, the threshold levels of GNI per capita are those established by the World Bank. Countries with less than $995 GNI per capita are classified as low-income countries, those with between $996 and $3,895 as lower-middle-income countries, those with between $3,896 and $12,055 as upper-middle-income countries, and those with incomes of more than $12,056 as high-in-come countries. The basic criteria for inclusion require that certain thresholds be met with regard to per capita GNI, a human assets index and an economic vulnerability index.3 As of March 2018, there were 47 LDCs (table F). Unless otherwise indicated, multi-year averages of growth rates are expressed as compound annual percentage rates of change. The convention followed is to omit the base year in a multi-year growth rate.