Polyolefins increased significantly in the first third of 2012, by around 20%, while polystyrene and PVC increased to a lesser extent. The following quarter saw a similar but opposite change in prices, with prices rising again in August and September and falling by around €51T4T in October compared to the previous month. Then, in the last quarter and in the first quarter of 2013, polyolefins prices rose at a similar rate to the previous quarter, with February prices some 51T4T higher than a year earlier.