Breaking down the Nazi-Soviet trade by periods?

[Die Neue Zeit]

The Non-Aggression Pact was one thing, but the trade between Nazi Germany and the Soviet Union was another. Is there any specific info on trade between the two countries during specific periods leading up to Operation Barbarossa? I'd like to know trade levels during the political liquidation of Poland, during the Phoney War, during the Battle of Britain, during the Axis campaign in the Balkans, etc.