3rl. over the entire period of the development decades a major probrem before nanydeveloping countries was a negative trend in the terms on which they exchangedCheir exports for imports. Between 1960 and the early years of the 19g0s netlosses in the purchasing power of exports caused by adverse changes in the terms oftrade were recorded in 62 of 99 atevelopinq countrles for which relevanE data areavailable. This negative trend was widespread, as all groups of developingcountries suffered significant declines in cheir terms of trade at some time duringthis period. Furthermore, as the rate of growth in the volume of clevelopi.ngcountry exports slowed over the course of the development decades cbeir terms oftrade also tended to worsen, limit.ing the capacity of Ehese countries to mai.ntainpast rates of inport absorption and re-enforcing the downward tendencies already atwork in many countries. For the least developed economies as a whote thepurchasing power of their exports declined in each development decade, indeed, atan average annual rate of I per cent since 1970. Because the disadvantagedcountries are precisely those characterizeal by economic circumstances leastfavourabre to a policy of lnternal deveropment based on their own timitedresources, the severe deterioration of their terms of trade has gravely affectedtheir ability to finance inports necessary to sustaln production and increasecapacity.
**Analysis**
The text discusses the challenges faced by developing countries in terms of their terms of trade, which affects their ability to finance imports and sustain production. The focus is on the economic aspect of the development process, specifically the impact of international trade on the economic growth and development of these countries.

**Category**
International trade