 From 1937 to the beginning of 1941, the Soviet Union served as the primary supplier to the ROCAF, and from October 1937 to January 1941, a total of 848 aircraft in 13 batches were ordered by the Chinese government and were supplied on credit, worth roughly 200 million dollars.In addition, there were 37 aircraft transferred to Chinese when Soviet force withdrew from China after the signing of Soviet–German Non-Aggression Pact.These aircraft included 563 fighters, including 252 I-152, 75 I-153, 132 I-16 Type 10, 75 I-16 Type 17 and rest being I-15 bis, which was not part of the purchase in the 13 batches.