The most complete way is to look at current accounts (Current account is total new saving minus total new investment for the year): increase of current account surplus or decrease of current account deficit is deleveraging. So for instance, between 2006 and 2011, the US current account deficit shrank from $800Bn to $468Bn, so $332Bn of deleveraging. China's surplus ballooned from $263Bn to $361Bn so $128Bn of de-leveraging (Source: IMF WEO Sep 2011 database). In theory you can't add them as China's surplus is mostly the mirror image of US deficit, but then they should shrink or balloon in lockstep. As they moved in oppsite direction, I think you can add them to get a rough idea of total deleveraging, so that's about $400Bn of total debt destruction or savings creation between those two countries. Of course that's total deleveraging in the country (public plus private).
As during that time, both governments have increased their debt by stimulus (top of my head $1.3 Tn for US, $600Bn for China-unaudited figures, just what I have in mind but that's a minimum) that's another $2Tn that should be added to figure out total private sector de-leveraging. So that would be $2.4Tn of private debt destruction between those two countries. You have to add big and small European current account shrinkages and others so that's a significant margin call on the global economy...