And the sharp decline in global prices for commodities such as oil and copper since last year have raised major challenges, especially in major oil-exporting countries such Angola and Nigeria where oil accounts for more than 90% of export earnings.
Its repayments were also limited to 3% of export earnings.
Soybeans are one of the most important sources of export earnings.
Oil provides about half the government's revenue and at least 80% of export earnings.
Its coffee sales last year were $425m, representing 36% of export earnings.
The result is increased dependence on oil, now accounting for 96% of export earnings versus 80% a decade ago.
He attributed most of that to the falling prices of electronics products, which account for 25percentt of export earnings.
Russia depends on oil and gas, which provide half the government's revenues and almost 70 percent of export earnings.
By 1900 tin completely superseded silver as Bolivia's primary export, accounting for more than half of export earnings.
Sugar production, generating about one-sixth of export earnings, occupies about four-fifths of the total arable land.
One way and another universities contribute £33.4 billion to the national economy, it concludes, including £5.3 billion of export earnings.
