the Global Debt Clock

From the website of The Economist, the Global Debt Clock.

Situation in 2001:

Situation in 2013 (forecasted):

Globally the debt has risen from USD 18 Trillion to USD 51 Trillion, 2.8 times as much, or a year-on-year growth of 9%. Very worrisome, since global growth has been much lower.

I am not sure if all numbers are correct. In the Malaysian situation for instance I read somewhere that government guarantees of debt are not counted in the overall number.

The debt in Singapore appears very high, but surely this must be offset by huge amounts of assets overseas which are much more valuable than the debt.