While I am not sure whether the Chinese yuan has appreciated by more than 30% against the US dollar since 2008 (I cannot produce that results using some data from the internet), it is a fact that it has appreciated. The issue is not just the appreciation against dollar, but also the appreciation of the US dollar against virtually all major currencies at the same time. The following table shows the appreciation of the US dollar since 11/09/2008.
US Dollar Appreciation of US dollar against major other currencies since 11/09/2008:
Table 1 Changes in US dollar against other major currencies, 11/09/2008 to 10/09/2015
|Appreciation of US dollar against major other currencies since 11/09/2008|
|Chinese Yuan Renminbi||0.932251339|
The US dollar appreciated 24%, 14%, 13% against the euro, the British pound and the Japanese yen respectively from then to yesterday. On the other hand, it depreciated about 7% against the Chinese yuan.