What is the fine-grained topic of the following text: During the 12-month period the average price of US clothing imports dropped to its lowest level in over 20 years, after the elimination of safeguard restrictions against US imports of certain items from China at the end of 2008 meant there was no upper limit to the supplies available and exporters were forced to lower their prices to compete for orders. Only return the topic.
Drop in Average Price of US Clothing Imports