Lots of infected PCs in China

The recent "Security Threat Report 2012" from Sophos has all sorts of interesting information in it. I found the data about the fraction of PCs that experienced a malware attack over a three-month period interesting. Here's the data from Sophos' report that describes this:

But if we use the number of on-line users in each country as an estimate of the total number of infected PCs in each country, the graph looks much different:

China's definitely a big problem, isn't it?